#include <iostream>
// #include <string>
// #include <vector>
// #include <set>
// #include <unordered_set>
// #include <map>
// #include <list>
// #include <algorithm>
// #include <numeric>
// #include <cmath>
// #include <bits/stdc++.h>
#define ll long long
#define yes cout << "YES\n"
#define no cout << "NO\n"
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define SORT(v) sort(v.begin(), v.end())
#define REVERSE(v) reverse(v.begin(), v.end())
#define REV_SORT(v) sort((v).begin(), (v).end(), greater<>())
#define vint vector<int>
#define vll vector<ll>
#define vch vector<char>
#define vstr vector<string>
#define u_set unordered_set
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define fast                     \
    ios::sync_with_stdio(false); \
    cin.tie(0);                  \
    cout.tie(0);
using namespace std;

void debug()
{
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif // ONLINE_JUDGE
}

void solve();

ll LCD(ll n, ll m)
{
    ll smaller = (n < m) ? n : m;
    for (ll i = 2; i <= smaller; ++i)
    {
        if (n % i == 0 && m % i == 0)
        {
            return i;
        }
    }
    return -1;
}

int32_t main()
{
    fast;
    // debug();
    int TestCase = 1;
    cin >> TestCase;
    while (TestCase--)
        solve();
    return 0;
}

void solve()
{
    ll n, m;
    cin >> n >> m;
    cout << LCD(n, m) << '\n';
}