Problem p03231 (python)

Fixed submission:
input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()

def gcd(a, b):
  while b > 0:
    a, b = b, a%b
  return a

def lcm(a, b):
  return a*b/gcd(a, b)

L = int(lcm(N,M))
x = 1
count = 0
while True:
    k = L*x
    flag = 1
    starti = 0
    startj = 0
    for i in range(starti, N):
        for j in range(startj, M):
            hoge = i*k/N+1
            fuga = j*k/M+1
            if(hoge < fuga):
                startj = j - 1
                break
            elif(hoge == fuga):
                if(S[i] != T[j]):
                    flag = 0
                    count += 1
                    break
        if(flag == 0):
            break
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1

Buggy submission (verdict: Runtime Error):
input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()

def gcd(a, b):
  while b > 0:
    a, b = b, a%b
  return a

def lcm(a, b):
  return a*b/gcd(a, b)

L = int(lcm(N,M))
x = 1
count = 0
if N >= M:
    big = N
    small = M
else:
    big = M
    small = N
    
while True:
    k = L*x
    flag = 1
    for j in range(small):
        left = 0
        right = big - 1
        while left <= right:
            mid = (left+right)//2
            if((mid-1)*k/big+1 == (j-1)*k/small+1):
                if(S[mid-1] != T[j-1]):
                    flag = 0
                    count += 1
                    break
                else:
                    break
            elif((mid-1)*k/big+1 > (j-1)*k/small+1):
                right = mid - 1
            else:
                left = mid + 1
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1

Buggy submission (verdict: Runtime Error):
input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()

def gcd(a, b):
  while b > 0:
    a, b = b, a%b
  return a

def lcm(a, b):
  return a*b/gcd(a, b)

L = int(lcm(N,M))
x = 1
count = 0
if N >= M:
    big = N
    small = M
else:
    big = M
    small = N
    
while True:
    k = L*x
    flag = 1
    for j in range(small):
        left = 0
        right = big - 1
        while left <= right:
            mid = (left+right)/2
            if((mid-1)*k/big+1 == (j-1)*k/small+1):
                if(S[mid-1] != T[j-1]):
                    flag = 0
                    count += 1
                    break
                else:
                    break
            elif((mid-1)*k/big+1 > (j-1)*k/small+1):
                right = mid - 1
            else:
                left = mid + 1
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1

Buggy submission (verdict: Runtime Error):
input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()

def gcd(a, b):
  while b > 0:
    a, b = b, a%b
  return a

def lcm(a, b):
  return a*b/gcd(a, b)

L = int(lcm(N,M))
x = 1
count = 0
if N >= M:
    big = N
    small = M
else:
    big = M
    small = N
    
while True:
    k = L*x
    flag = 1
    left = 0
    right = big - 1
    for j in range(small):
        while left <= right:
            mid = (left+right)/2
            if((mid-1)*k/big+1 == (j-1)*k/small+1):
                if(S[mid-1] != T[j-1]):
                    flag = 0
                    count += 1
                    break
                else:
                    break
            elif((mid-1)*k/big+1 > (j-1)*k/small+1):
                right = mid - 1
            else:
                left = mid + 1
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1

Buggy submission (verdict: Runtime Error):
input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()

def gcd(a, b):
  while b > 0:
    a, b = b, a%b
  return a

def lcm(a, b):
  return a*b/gcd(a, b)

L = int(lcm(N,M))
x = 1
count = 0
if N >= M:
    big = N
    small = M
else:
    big = M
    small = N
    
while True:
    k = L*x
    flag = 1
    left = 0
    right = big - 1
    for j in range(small):
        while left <= right:
            mid = (left+right)/2
            if((mid-1)*k/big+1 == (j-1)*k/small+1):
                if(S[mid-1] != T[j-1]):
                    flag = 0
                    count += 1
                    break
            elif((mid-1)*k/big+1 > (j-1)*k/small+1):
                right = mid - 1
            else:
                left = mid + 1
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1

Buggy submission (verdict: Runtime Error):
input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()

def gcd(a, b):
  while b > 0:
    a, b = b, a%b
  return a

def lcm(a, b):
  return a*b/gcd(a, b)

L = int(lcm(N,M))
x = 1
count = 0
if N >= M:
    big = N
    small = M
else:
    big = M
    small = N
    
while True:
    k = L*x
    flag = 1
    left = 0
    right = big - 1
    for j in range(small):
        while left <= right:
            mid = (left+right)/2
            if((mid-1)*k/big+1 == (j-1)*k/small+1):
                if(S[mid-1] != T[j-1]):
                    flag = 0
                    count += 1
                    break
            elif((mid-1)*k/big+1 == (j-1)*k/small+1):
                right = mid - 1
            else:
                left = mid + 1
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1

Buggy submission (verdict: Runtime Error):
import math

input_lines = input().split()
N = int(input_lines[0])
M = int(input_lines[1])
S = input()
T = input()
#print(N,M,S[0],T[0])
L = int(N*M/math.gcd(N,M))
x = 1
count = 0
while True:
    k = L*x
    flag = 1
    for i in range(N):
        for j in range(M):
            if((i-1)*k/N+1 == (j-1)*k/M+1):
                if(S[i-1] != T[j-1]):
                    flag = 0
                    count += 1
                    break
    if(flag == 1):
        print(k)
        break
    if(count == 2):
        print(-1)
        break
    x += 1