import java.util.*;
import java.io.*;
import java.math.*;
 
public class Main{
    public static BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));
    public static PrintWriter output = new PrintWriter(System.out);
    public static Scanner sc = new Scanner(System.in);
    public static final int INFI = Integer.MAX_VALUE;
    public static final long INFL = Long.MAX_VALUE;
    public static final int MOD = 1000000007;

    public static void main(String[] args) throws IOException{
        StringTokenizer st;
        //st = new StringTokenizer(buff.readLine());
        String S = sc.next();
        boolean ok = false;
        for(long i=(long)1e6;i<=(long)1e7;i++) {
            String s = Long.toString(i*i);
            if(s.substring(7,s.length()).equals(S)) ok = true;
        }
        output.println(ok?"YES":"NO");
        output.flush();
    }
}