Fortran90で学習した内容をpythonに書き換えようとしましたが、問題発生しました。

前提・実現したいこと

以下のコードを動かしてt,sigma1_c, sigma2_c, sigma3_c, qを求めたい。

発生している問題・エラーメッセージ

エラーメッセージ
File "<ipython-input-15-7b6d1feb2de7>", line 51
    reurn kf(x = 2) * r3
           ^
SyntaxError: invalid syntax

該当のソースコード

python
1ソースコード
2import math
3def sigma_1(x):
4    return math.floor(x / 16)
5def sigma_2(x, sigma1):
6    return math.floor((x - 16 * sigma1) / 4)
7def sigma_3(x, sigma1, sigma2):
8    return x - 16 * sigma1 - 4 * sigma2
9def q64(x, y, z):
10    return 16 * x + 4 * y + z
11r2 = 100
12r3 = 1000
13r4 = 10000
14atp = 2
15adp = 2
16pi = 2
17def kf(x = 0):
18    return 0.11 * atp
19def kf(x = 1):
20    return 0.12
21def kf(x = 2):
22     return 1.6 * 10 ** (-3)
23def kf(x =3):
24    return 1.2 * 10 ** (-3)
25def kb(x = 0):
26    return 2.5 * 10 ** (-5)
27def kb(x = 1):
28    return 4.3 * 10 ** (-5)
29def kb(x = 2):
30    return 1.8 * 10 ** (-4) * adp
31def kb(x = 3):
32    return 4.8e-10 * pi
33q = 0
34while q <= 63:
35    sigma1 = sigma_1(q)
36    sigma2 = sigma_2(q, sigma1)
37    sigma3 = sigma_3(q, sigma1, sigma2)
38    def k(q, n = 0):
39        return kf(sigma1)
40    def k(q, n = 1):
41        return kb(sigma1)
42    def k(q, n = 2):
43        return kf(sigma2)
44    def k(q, n = 3):
45        return kb(sigma2)
46    def k(q, n = 4):
47        return kf(sigma3)
48    def k(q, n = 5):
49        return kb(sigma3)
50    q += 1
51def k(q = 22, n = 4):
52    reurn kf(x = 2) * r3
53def k(q = 23, n = 0):
54    return kf(x = 1) * r2
55def k(q = 25, n = 2):
56    return kf(x = 2) * r3
57def k(q = 29, n = 4):
58    return kf(x = 1) * r2
59def k(q = 30, n = 2):
60    return kf(x = 3) * r4
61def k(q = 37, n = 0):
62    return kf(x = 2) * r3
63def k(q = 39, n = 4):
64    return kf(x = 3) * r4
65def k(q = 53, n = 2):
66    return kf(x = 1) * r2
67def k(q = 57, n = 0):
68    return kf(x = 3) * r4
69q = 0
70while q <= 63:
71    k0(q) = 0
72    i = 0
73    while i <= 5:
74        k0(q) = k0(q) + k(q, i)
75        i += 1
76    q += 1
77q = 0
78while q <= 63:
79    c(q, i = 0) =k(q, i = 0) / k0(q)
80    i = 0
81    while i <= 5:
82        c(q, i) = c(q, i - 1) + k(q, i) / k0(q)
83        i += 1
84    q += 1
85q = 0
86sigma1_c = 0
87sigma2_c = 0
88sigma3_c = 0
89sigma1 = sigma_1(q)
90sigma2 = sigma_2(q, sigma1)
91sigma3 = sigma_3(q, sigma1, sigma2)
92j = 1
93import random
94while j <= 100:
95    tau = 1 / k0(q)
96    x = random.random()
97    dt = - tau * log(x)
98    t = t + dt
99    y = random.random()
100    if y < c(q, n = 0):
101        sigma1 = sigma1 + 1
102        sigma1_c = sigma1_c + 1
103        if (sigma1 > 3):
104            sigma1 = 0
105    elif y < c(q, n = 1):
106        sigma1 = sigma1 - 1
107        sigma1_c = sigma1_c - 1
108        if sigma1 < 0:
109            sigma1 = 3
110    if y < c(q, n = 2):
111        sigma2 = sigma2 + 1
112        sigma2_c = sigma2_c + 1
113        if (sigma2 > 3):
114            sigma2 = 0
115    elif y < c(q, n = 3):
116        sigma2 = sigma2 - 1
117        sigma2_c = sigma2_c - 1
118        if sigma2 < 0:
119            sigma2 = 3
120    if y < c(q, n = 4):
121        sigma3 = sigma3 + 1
122        sigma3_c = sigma3_c + 1
123        if (sigma3 > 3):
124            sigma3 = 0
125    elif y < c(q, n = 5):
126        sigma3 = sigma3 - 1
127        sigma3_c = sigma3_c - 1
128        if sigma3 < 0:
129            sigma3 = 3
130    q = q64(sigma1, sigma2, sigma3)
131print (t, sigma1_c, sigma2_c, sigma3_c, q)