费马小定理

#include <iostream>
#include <cstdio>
#include <algorithm>
 
using namespace std;
 
#define ll long long

// a / b mod p
//满足条件 b 和 p互质
// a / b mod p = a * b^(p - 2) mod p
 
ll gcd(ll a, ll b){
    return b == 0 ? a : gcd(b, a % b);
}
 
ll ksm(long long a, long long b, long long mod){
    ll ans = 1;
    while(b){
        if(b & 1) ans = ans * a % mod;
        a = a * a % mod;
        b >>= 1;
    }
     
    return ans;
}
 
void solve(){
     
    int n;
    scanf("%d", &n);
    while(n--){
        long long p, y;
        scanf("%lld%lld", &y, &p);
        if(gcd(p, y) != 1) printf("-1
");
        else printf("%lld
", ksm(y, p - 2, p));
    }
}
 
int main(){
     
    solve();
     
    return 0;
}