#include<bits/stdc++.h>
using namespace std;
int main()
{   
    int k1,k2,k3,k4;
    for(int i=1000;i<=9999;i++)
    {
        k1 = i / 1000;
        k2 = i / 100 % 10;
        k3 = i / 10 % 10;
        k4 = i % 10;
        if(k1 == k2)
        {
            if(k3 == k4)
            {
                int t = sqrt(i);
                if(sqrt(i) == t)
                {
                    cout<<i;
                }
            }
        }
    }
    return 0;
}
/**************************************************************
	Problem: 1092
	User: wuyichen
	Language: C++
	Result: Accepted
	Time:3 ms
	Memory:2072 kb
****************************************************************/