diff --git a/8.py b/8.py
new file mode 100644
index 0000000..271eb6e
--- /dev/null
+++ b/8.py
@@ -0,0 +1,44 @@
+with open("8.txt") as f:
+    ins = []
+    for line in f:
+        ins.append(line.strip())
+
+def term(ins):
+    f = set()
+    f2 = set()
+    acc = 0
+    ip = 0
+    while True:
+        if ip >= len(ins):
+            break
+        i = ins[ip]
+        if ip in f:
+            if ip in f2:
+                return None
+            f2.add(ip)
+        f.add(ip)
+        # print(ip, i)
+        c, v = i.split(" ")
+        v = int(v)
+        if c == "acc":
+            acc += v
+        elif c == "jmp":
+            ip = ip + v - 1
+        ip += 1
+    return acc
+
+for i in range(len(ins)):
+    l = ins[i]
+    if not (l.startswith("jmp") or l.startswith("nop")): continue
+    orig = l
+    if l.startswith("jmp"):
+        new = l.replace("jmp", "nop")
+    elif l.startswith("nop"):
+        new = l.replace("nop", "jmp")
+    ins[i] = new
+    r = term(ins)
+    if r is None:
+        ins[i] = orig
+    else:
+        print(r)
+        break
diff --git a/8.txt b/8.txt
new file mode 100644
index 0000000..62e61dd
--- /dev/null
+++ b/8.txt
@@ -0,0 +1,634 @@
+acc +15
+acc +2
+acc -14
+jmp +362
+acc +22
+nop +236
+jmp +474
+acc +10
+jmp +1
+acc +0
+jmp +236
+acc +10
+acc +14
+jmp +334
+acc +12
+acc -1
+jmp +478
+jmp +90
+jmp +208
+acc +49
+jmp +94
+acc +2
+acc -8
+jmp +375
+nop +21
+acc +0
+acc +10
+nop +25
+jmp +492
+nop +182
+acc +49
+acc -12
+jmp -14
+acc -16
+jmp +140
+acc -3
+acc -18
+acc +28
+acc -6
+jmp +558
+acc +2
+acc +27
+nop +438
+acc +41
+jmp +508
+acc +13
+jmp +117
+acc +21
+acc -13
+acc +34
+jmp +1
+jmp +1
+nop +451
+acc +28
+acc +31
+acc +31
+jmp +280
+acc +32
+acc +35
+acc -18
+jmp +509
+acc -15
+acc -8
+nop +288
+acc -16
+jmp +376
+acc -19
+acc -8
+acc +11
+acc +10
+jmp +50
+acc +19
+nop -58
+acc -9
+jmp +43
+acc +10
+acc +2
+nop -63
+jmp +280
+acc -7
+jmp +175
+jmp +69
+acc +16
+acc +9
+acc -2
+acc -5
+jmp +276
+nop +195
+acc +50
+acc -8
+jmp -55
+nop +1
+nop -78
+acc +31
+jmp +535
+acc +9
+acc +33
+acc +4
+acc +48
+jmp +8
+acc +30
+acc +42
+acc +18
+acc +37
+jmp -69
+nop +121
+jmp +44
+acc +3
+acc +33
+acc -6
+acc +37
+jmp +403
+acc -6
+jmp +245
+jmp -93
+acc +5
+jmp +406
+jmp -26
+nop -47
+jmp +239
+acc +7
+acc +31
+acc +14
+acc +0
+jmp +291
+acc +46
+jmp +394
+acc +44
+acc +36
+nop +45
+jmp +137
+acc -16
+acc +10
+acc -4
+acc +7
+jmp +76
+acc +24
+jmp +93
+acc +17
+acc +0
+acc +6
+acc +4
+jmp +385
+acc -8
+acc +49
+acc +28
+jmp +95
+nop +12
+acc +33
+jmp +153
+nop +254
+acc +18
+acc -16
+acc +50
+jmp +299
+acc +27
+acc +47
+acc -17
+jmp -15
+acc +35
+acc +14
+jmp +204
+jmp +93
+acc +46
+nop -5
+nop -158
+jmp +221
+jmp +321
+acc -2
+acc +49
+acc +3
+acc -17
+jmp -52
+jmp +7
+nop +52
+acc +25
+jmp +376
+acc -3
+nop -133
+jmp +32
+jmp +328
+nop +374
+acc +37
+acc +6
+jmp +92
+acc +47
+nop +394
+jmp -13
+jmp -170
+acc +9
+jmp -47
+acc -18
+acc +27
+jmp +1
+acc +3
+acc -5
+jmp +337
+acc +21
+jmp +364
+acc +24
+acc +43
+acc +50
+jmp +58
+jmp -18
+acc +30
+jmp +144
+nop +5
+acc +50
+nop +245
+nop +133
+jmp +270
+jmp -22
+nop -76
+jmp +398
+acc +40
+acc +30
+jmp +361
+acc +36
+acc +30
+jmp +392
+acc -17
+nop +71
+acc -12
+jmp +102
+acc +17
+jmp +283
+acc -16
+jmp +65
+nop -2
+jmp +149
+jmp -103
+jmp -179
+acc +46
+jmp +289
+acc +48
+jmp +114
+acc +13
+jmp +114
+nop +215
+nop -89
+jmp +337
+acc -2
+acc +2
+acc -7
+jmp -18
+jmp -51
+acc +30
+acc +43
+acc +28
+jmp -188
+acc +36
+acc +7
+acc -5
+acc +38
+jmp +88
+jmp +225
+acc -14
+acc -3
+acc -15
+jmp +66
+acc +7
+acc +43
+nop -210
+acc -9
+jmp +109
+acc -10
+jmp +242
+acc -5
+acc +15
+acc +8
+jmp +310
+acc +31
+acc -2
+acc +11
+acc -15
+jmp +103
+acc +32
+jmp -92
+acc -10
+acc +6
+acc -1
+jmp -131
+acc +43
+acc +30
+acc +13
+acc +33
+jmp +25
+acc +9
+acc -14
+acc +19
+acc +44
+jmp -50
+acc -8
+acc +9
+jmp +312
+jmp -96
+acc -3
+acc -3
+acc +24
+jmp +94
+acc -15
+jmp +61
+acc +19
+nop -89
+acc +24
+nop -94
+jmp +5
+acc -13
+acc +25
+acc +42
+jmp +1
+jmp +137
+acc +44
+acc +44
+acc +41
+jmp +152
+jmp +144
+acc -1
+nop +293
+jmp -120
+acc -17
+nop -171
+acc +27
+jmp -173
+jmp +231
+acc +3
+jmp +109
+acc +18
+acc +32
+acc -14
+acc -8
+jmp +177
+acc +28
+jmp -134
+nop +277
+jmp -124
+jmp +167
+nop +274
+acc +6
+acc +43
+acc +10
+jmp -320
+acc +28
+acc -9
+acc +22
+jmp -90
+jmp -203
+jmp -133
+jmp -6
+jmp -181
+jmp +170
+acc +40
+acc +5
+jmp -274
+acc +36
+acc +24
+nop +6
+jmp -339
+jmp -251
+acc +10
+acc +10
+jmp -347
+jmp +263
+acc +37
+jmp -201
+acc -11
+acc +42
+jmp +153
+nop -179
+acc -9
+jmp +8
+jmp -289
+jmp -25
+acc +45
+jmp -142
+acc +42
+acc -10
+jmp +83
+acc +43
+acc +3
+acc -6
+jmp -222
+acc +41
+acc +14
+acc +7
+acc +2
+jmp -35
+jmp +168
+acc +11
+acc +18
+acc +8
+acc -4
+jmp -203
+acc +44
+jmp +10
+nop -184
+acc +0
+jmp +91
+acc -5
+nop +226
+acc +46
+acc -10
+jmp -15
+jmp -321
+acc +0
+acc +33
+jmp +82
+jmp +1
+acc -12
+acc +30
+jmp +152
+acc +6
+jmp -208
+acc +43
+jmp +39
+acc +23
+acc +23
+acc +24
+acc +26
+jmp -390
+acc +15
+acc +3
+acc +14
+acc +46
+jmp -239
+acc -10
+acc +19
+jmp +167
+acc +46
+acc +0
+jmp -280
+acc -7
+jmp -107
+acc +13
+jmp -76
+acc +48
+jmp -65
+nop +23
+nop -89
+acc +47
+jmp -304
+acc -5
+jmp +1
+acc +50
+acc +37
+jmp -129
+acc +27
+jmp +1
+jmp -212
+acc +18
+acc +29
+acc +1
+jmp -74
+acc +24
+acc -12
+jmp -173
+acc -18
+acc -6
+nop -156
+jmp -309
+acc +46
+acc -13
+acc +41
+acc +11
+jmp -188
+acc +32
+jmp -190
+acc +31
+acc +30
+jmp -122
+acc -7
+jmp +37
+acc +2
+acc +16
+acc +45
+acc +44
+jmp -376
+acc +47
+jmp +1
+jmp -147
+acc +47
+acc -18
+acc -1
+acc +2
+jmp -152
+acc +12
+acc -8
+jmp +90
+nop +67
+acc +9
+jmp +1
+jmp -377
+jmp +1
+jmp -238
+jmp +1
+acc +47
+acc +7
+acc +31
+jmp -427
+acc +10
+acc +13
+nop +13
+jmp -8
+nop -292
+acc +11
+nop -203
+jmp -164
+jmp -19
+acc +31
+jmp -289
+acc -7
+acc -16
+acc +35
+jmp -333
+jmp -500
+acc +32
+acc +29
+acc +18
+acc +14
+jmp -161
+jmp -60
+jmp +6
+acc +4
+nop -108
+acc +27
+jmp +2
+jmp -133
+acc +2
+jmp -103
+acc +40
+nop -512
+acc +48
+jmp -196
+acc +47
+acc +40
+nop -346
+acc -2
+jmp -530
+acc +17
+nop -31
+acc +1
+jmp -74
+acc -15
+acc +4
+nop -330
+acc +32
+jmp -115
+acc -3
+jmp +1
+acc +14
+acc +31
+jmp -352
+jmp -10
+acc +18
+jmp -322
+acc +41
+jmp +59
+acc -16
+nop -359
+acc +29
+acc +26
+jmp -418
+acc +10
+acc +47
+jmp -519
+acc -5
+nop +40
+acc +30
+jmp -195
+acc +31
+acc +3
+acc +8
+jmp -10
+acc -12
+acc +21
+acc -1
+jmp +30
+jmp -341
+acc -5
+jmp -405
+acc -13
+jmp -170
+acc +24
+acc -16
+acc +20
+acc +17
+jmp -145
+acc +42
+acc +33
+jmp -395
+nop -142
+acc +45
+acc +15
+jmp -399
+nop -223
+jmp -299
+jmp -453
+acc -6
+nop -498
+acc +42
+jmp -112
+acc +39
+acc +46
+acc +4
+acc +27
+jmp -234
+jmp +1
+acc +45
+acc +47
+jmp -307
+jmp -378
+jmp -431
+acc +13
+acc +29
+jmp -282
+acc +4
+acc -3
+acc +37
+acc +40
+jmp -32
+nop -148
+acc +38
+acc +40
+acc +18
+jmp -171
+nop -546
+jmp -490
+acc +36
+jmp -514
+acc +27
+acc -10
+nop -560
+acc +44
+jmp +1
diff --git a/8ex.txt b/8ex.txt
new file mode 100644
index 0000000..178df53
--- /dev/null
+++ b/8ex.txt
@@ -0,0 +1,9 @@
+nop +0
+acc +1
+jmp +4
+acc +3
+jmp -3
+acc -99
+acc +1
+jmp -4
+acc +6