#include <bits/stdc++.h>
using namespace std;

main()
{
    //ifstream cin("10110.in");
    //ofstream cout("10110.out");
    while (true)
    {
        int n, count = 0;

        cin >> n;

        int temp = sqrt(n);

        if (n == 0)
        {
            break;
        }
        else
        {
            if (temp * temp == n)
            {
                cout << "YES" << endl;
            }
            else
                cout << "NO" << endl;
        }
    }
}