Submit python solution

Hi, I am quite new to codechef and also submitted my first problem. I am extremely sorry if this is not the right question to post. I am having an issue regarding submission. The issue is when I submit the solution against the custom input which is derived from problem description, it works!! (The program able to produce the right result). But then when I submit the solution not against the custom input, I get ‘NZEC’. Below is my attached code. If there is a problem with the code, please help me out. I couldn’t move one step further. The solution is for the problem

def gcd(a,b):
   if a == b: return a
   if a > b: return gcd(a-b,a)
   return gcd(a,b-a)

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

testcases = int(input())
for t in range(testcases):
    N,a,b,k = map(int,input().split())
    x = N//a
    y = N//b
    z = N//lcm(a,b)
    print('Win' if x+y-2*z >= k else 'Lose')

Maybe the problem is with your gcd function: