//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pp pair<int,int>
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define ld long double
#define al(a) (a).begin(),(a).end()
#define mk make_pair
#define check cout<<"?"<<endl;

ll MOD=1000000007;
ll mod=998244353;
int inf=1000001000;
ll INF=1e18+5;

int main(){
    ll t; cin>>t;
    vector<ll> pr(5000001,1);
    pr[1]=0;
    for(ll i=2;i<=5000000;i++){
        if(pr[i]==0) continue;
        for(ll j=2*i;j<=5000000;j+=i) pr[j]=0;
    }
    rep(_,t){
        ll a,p; cin>>a>>p;
        if(pr[p]==0){
            printf("-1\n");
            continue;
        }
        a%=p;
        if(a==0){
            printf("0\n");
            continue;
        }
        printf("1\n");
    }
}