Buggy python submission (verdict: Runtime Error):
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,Input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
s = input()
t = input()
g = math.gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
s = input()
t = input()
g = math.gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
from math import gcd
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
from math import gcd
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(l):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)



Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if (M*n)%N==0:
        m = (M*n)//N
        flag = S[n]==T[m]
        if not flag:
            break

if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if (M*n)%N==0:
        m = (M*n)//N
        flag = m<M
        if flag:
            flag = S[n]==T[m]
        if not flag:
            break

if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):

import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if (M*n)%N==0:
        m = (M*n)//N
        flag = m<M
        flag = S[n]==T[m]
        if not flag:
            break

if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if (M*n)%N==0:
        m = (M*n)//N
        flag = (S[n]==T[m])
        if not flag:
            break
if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if (M*n)%N==0:
        m = (M*n)//N
        flag = (S[n]==T[m])
        if !flag:
            break
if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if (M*n)%N==0:
        m = M*n//N
        flag = S[n]==T[m]
        if not flag:
            break

if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if M*n%N==0:
        m = M*n//N
        flag = S[n]==T[m]
        if not flag:
            break
if flag:
    print(N*M//math.gcd(N,M))
else:
    print(-1)


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if M*n%N==0:
        m = M*n//N
        flag = S[n]==T[m]
        if not flag:
            break
if not flag:
    print(-1)
else:
    print(N*M//math.gcd(N,M))


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if M*n%N==0:
        m = M*n//N
        flag = S[n]==T[m]
    if not flag:
        break
if not flag:
    print(-1)
else:
    print(N*M//math.gcd(N,M))


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)

Buggy python submission (verdict: Runtime Error):
from math import gcd
N,M = map(int,input().split())
S = input()
T = input()

flag = True
for n in range(N):
    if M*n%N==0:
        m = M*n//N
        flag = S[n]==T[m]
    if not flag:
        break
if not flag:
    print(-1)
else:
    print(N*M//gcd(N,M))


Fixed submission:
def gcd(a, b):
	while b:
		a, b = b, a % b
	return a
    
N,M = map(int,input().split())
s = input()
t = input()
g = gcd(N,M)
l = N*M//g

n = N//g
m = M//g

ans = l

for i in range(g):
    if s[i*n]!=t[i*m]:
        ans = -1
        break
print(ans)