样例过了，但无缘无故UKE，求助。

#include<bits/stdc++.h>
using namespace std;

int t;
int gcd(int x,int y)
{
    if(x == 0)return y;
    return gcd(y%x,x);
}
int main()
{
    cin >>t;
    int a,b;
    for(int i = 0; i < t; i++)
    {
        cin >>a>>b;
        if(a == 0)
        {
            cout <<b<<"\n";
            continue;
        }
        if(b == 0)
        {
            cout <<a<<"\n";
            continue;
        }
        cout <<gcd(a,b)<<"\n";
    }
}