Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):

    return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

r = ["*" for i in range(L)]
s = 0
t = 0
f = False

s_step = L // N
t_step = L // M
i = 0
j = 0
while s < L:
    r[s] = S[i]
    s += s_step
    i += 1

while t < L:
    if r[t] == T[j]:
        t += t_step
        j += 1
        continue
    elif r[t] == "*":
        r[t] = T[j]
        t += t_step
        j += 1
    else:
        f = True
        break
if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

r = ["*" for i in range(L)]
f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
S = input()
T = input()
import sys
sys.setrecursionlimit(20000)
def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

r = ["*" for i in range(L)]
f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
S = input()
T = input()

def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)

def lcm(a, b):
    return a * b // gcd(b, a%b)
L = lcm(N, M)

r = ["*" for i in range(L)]
f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N-1:
            break
        if t > M -1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break


if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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

L = lcm(N, M)

r = ["*" for i in range(L)]
s = 0
t = 0
f = False

s_step = L // N
t_step = L // M
j = 0
m = 0

for i in range(L):
    if i == 0:
        if S[0] == T[0]:
            r[i] = S[i]
            j += 1
            m += 1
            continue
        else:
            f = True
            break

    if i % s_step == 0 and j < N:
        if r[i] == "*":
            r[i] = S[j]
            j += 1
        else:
            if r[i] != S[j]:
                f = True
                break
            else:
                j += 1

    if i % t_step == 0 and m < M:
        if r[i] == "*":
            r[i] = T[m]
            m += 1
        else:
            if r[i] != T[m]:
                f = True
                break
            else:
                m += 1
if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

r = ["*" for i in range(L)]
s = 0
t = 0
f = False

s_step = L // N
t_step = L // M
j = 0
m = 0

for i in range(L):
    if i == 0:
        if S[0] == T[0]:
            r[i] = S[i]
            j += 1
            m += 1
            continue
        else:
            f = True
            break

    if i % s_step == 0 and j < N:
        if r[i] == "*":
            r[i] = S[j]
            j += 1
        else:
            if r[i] != S[j]:
                f = True
                break
            else:
                j += 1

    if i % t_step == 0 and m < M:
        if r[i] == "*":
            r[i] = T[m]
            m += 1
        else:
            if r[i] != T[m]:
                f = True
                break
            else:
                m += 1

if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

r = ["*" for i in range(L)]
s = 0
t = 0
f = False

s_step = L // N
t_step = L //M
i = 0
j = 0
while s < L:
    r[s] = S[i]
    s += s_step
    i += 1


while t < L:
    if r[t] == T[j]:
        t += t_step
        j += 1
        continue
    elif r[t] == "*":
        r[t] = T[j]
        t += t_step
        j += 1
    else:
        f = True
        break
if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
S = input()
T = input()


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    else:
        return a if b == 0 else gcd(b, a % b)


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


L = lcm(N, M)

r = ["*" for i in range(L)]
s = 0
t = 0
f = False

s_step = L // N
t_step = L //M
i = 0
j = 0
while s < L:
    r[s] = S[i]
    s += s_step
    i += 1


while t < L:
    if r[t] == T[j]:
        t += t_step
        j += 1
        continue
    elif r[t] == "*":
        r[t] = T[j]
        t += t_step
        j += 1
    else:
        f = True
        break
if f:
    print(-1)
else:
    print(L)


Fixed submission:
N, M = map(int, input().split())
S = input()
T = input()
# def gcd(a, b):
#     if a < b:
#         return gcd(b, a)
#     else:
#         return a if b == 0 else gcd(b, a % b)

import fractions
def lcm(a, b):
    return a * b // fractions.gcd(b, a % b)


L = lcm(N, M)

f = False

s_step = L // N
t_step = L // M
sL = lcm(s_step, t_step)
s = 0
t = 0

for i in range(0, L, sL):
    if i == 0:
        if S[i] == T[i]:
            continue
        else:
            f = True
            break
    else:
        s = i // s_step
        t = i // t_step
        if s > N - 1:
            break
        if t > M - 1:
            break
        if S[s] == T[t]:
            continue
        else:
            f = True
            break

if f:
    print(-1)
else:
    print(L)