http://acm.hust.edu.cn/vjudge/contest/view.action?cid=29821#problem/B
// File Name: bo_jwolf2.cpp
// Author: rudolf
// Created Time: 2013年08月21日 星期三 09:13:02
#include<vector>
#include<list>
#include<map>
#include<set>
#include<deque>
#include<stack>
#include<bitset>
#include<algorithm>
#include<functional>
#include<numeric>
#include<utility>
#include<sstream>
#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<ctime>
using namespace std;
int main()
{
long long n ;
while( scanf( "%lld" , &n ) != EOF && n )
{
long long temp = sqrt( n ) ;
if( temp * temp != n )
{
cout << "no" << endl ;
}
else
{
cout << "yes" << endl ;
}
}
return 0;
}