#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, srt, end) for (long long i = (srt); i < (long long)(end); i++)

#define NMAX 5000100
bool primes[NMAX];

int main(){
    rep(i, 2, NMAX) primes[i] = true;
    rep(i, 2, NMAX) {
        for(ll j = i * 2; j <= NMAX; j += i) primes[j] = false;
    }
    ll T = 0;
    cin >> T;
    rep(test, 0, T){
        ll a, p;
        cin >> a >> p;
        if(!primes[p]) {
            cout << -1 << endl;
            continue;
        }
        ll rem = a % p;
        ll cur = rem, pw = rem, cnt = 0;
        while(cur != 0 && cnt < p * (p+1) / 2) {
            cnt++;
            cur *= pw;
            cur %= p;
            pw *= rem;
            pw %= p;
        }
        cout << cur << endl;
    }
    return 0;
}