Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
if s[0]==t[0]:
  X=[""]*(L+1)
  print(X)
else:
  print(-1)
  exit()
for i in range(1,g):
  X[int(i*L/n)+1]=s[i]
for i in range(1,g):
  if X[int(i*L/m)+1] !="":
    if X[int(i*L/m)+1] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*(L+1)
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)+1]=s[i]
for i in range(1,m):
  if X[int(i*L/m)+1] !="":
    if X[int(i*L/m)+1] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*L+1
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)+1]=s[i]
for i in range(1,m):
  if X[int(i*L/m)+1] !="":
    if X[int(i*L/m)+1] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*(10**6+1)
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)+1]=s[i]
for i in range(1,m):
  if X[int(i*L/m)+1] !="":
    if X[int(i*L/m)+1] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*(10**5+1)
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)+1]=s[i]
for i in range(1,m):
  if X[int(i*L/m)+1] !="":
    if X[int(i*L/m)+1] !=t[i]:
      print(-1)
      exit()
print(L)


Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

if n<m:
  n,m=m,n
  s,t=t,s

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*(10**5)
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)]=s[i]
for i in range(1,m):
  if X[int(i*L/m)] !="":
    if X[int(i*L/m)] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*(L*2)
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)]=s[i]
for i in range(1,m):
  if X[int(i*L/m)] !="":
    if X[int(i*L/m)] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
if s[0]==t[0]:
  X=[""]*L
else:
  print(-1)
  exit()
for i in range(1,n):
  X[int(i*L/n)]=s[i]
for i in range(1,m):
  if X[int(i*L/m)] !="":
    if X[int(i*L/m)] !=t[i]:
      print(-1)
      exit()
print(L)

Fixed submission:
n,m=map(int,input().split())
s=input()
t=input()

def gcd(x,y):
  r=x%y
  return gcd(y,r) if r else y
#最小公倍数
def lcm(x, y):
    return (x * y) // gcd(x, y)

L=lcm(n,m)
g=gcd(n,m)
for i in range(g):
  if s[int(i*n/g)]!=t[int(i*m/g)]:
    print(-1)
    exit()
print(L)