#define task ""
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int nmax = int(1e6) + 10;

bool check (ll x)
{
    for (ll i = 2; i <= sqrt(x); ++i)
    if (x % i == 0) return false;
    return x > 1;
}
ll tt;
int main()  
{
  //freopen(task".inp" , "r" , stdin);
  //freopen(task".out" , "w" , stdout);

  ios::sync_with_stdio(false);
  cin.tie(0);
 
  cin >> tt;
  while (tt--)
  {
    ll a, b;
    cin >> a >> b;
    if (b - a != 1) cout << "NO";
    else if (check(a + b)) cout << "YES";
    else cout << "NO";
    cout << '\n';
  }
  return 0;
}

#include <iostream>
using namespace std;
int t, a, b, to;
bool csnt()
{
    if(to < 2) return false;
    if(to == 2 || to == 3) return true
    for(int i = 2; i <= sqrt(to); i++)
        if(to % i == 0) return false;
    return true;
}
int main() 
{
    cin >> t
    while(t--)
    {
        cin >> a >> b;
        to = b*b - a*a;
        if(csnt()) cout << "YES\n";
        else cout << "NO\n";
    }
    return 0;
}

$#khanhtaon$