872. Maximum common divisor

Given n Right integer ai,bi, Please find the greatest common divisor of each logarithm .

Input format
The first line contains integers n.

Next n That's ok , Each line contains an integer pair ai,bi.

Output format
The output, n That's ok , Each line outputs the maximum common divisor of an integer pair .

Data range
1≤n≤105,
1≤ai,bi≤2×109
sample input ：
2
3 6
4 6
sample output ：
3
2

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

int gcd(int a, int b)
{
    
    return b ? gcd(b, a % b) : a;
}

int main()
{
    
    cin >> n;
    int a, b;
    for(int i=0; i<n; i++) {
    
        cin >> a >> b;
        cout << gcd(a ,b) << endl;
    }
    return 0;
}