#include <algorithm>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
using namespace std;
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define All(v) (v).begin(), (v).end()
#define pb push_back
#define MP(a, b) make_pair((a), (b))
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;

vector<bool> sieve(int x) { // range...[0,x]
    vector<bool> flags(x + 1, true);
    flags[0] = false, flags[1] = false;
    for(int i = 2; i * i <= x; i++) {
        if(!flags[i])
            continue;
        for(int mult = i * i; mult <= x; mult += i)
            flags[mult] = false;
    }
    return flags;
}

int main() {
    int T;
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> T;
    auto primes = sieve(5000000);
    while(T--) {
        ll A, P;
        cin >> A >> P;
        if(primes[P]) {
            A = A % P;
            if(A == 0) {
                cout << 0 << endl;
            } else {
                cout << 1 << endl;
            }
        } else {
            cout << -1 << endl;
        }
    }
    return 0;
}