#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<math.h>
#include<map>
#include<iomanip>
#include<queue>

const long long mod=1e8;

using namespace std;

int main(){
	string s;
	cin >> s;
	long long n=0;
	for(int i=0;i<s.size();i++){
		n*=10;
		n+=s[i]-'0';
		n%=mod;
	}
	
	for(long long i=1;i<=mod;i++){
		long long bb=(i%mod*i%mod)%mod;
		long long aa=(n+bb)%mod;;
		long double a=sqrt(aa);
		a+=0.5;
		if((long long)(a)*(long long)(a)==aa && aa>bb){
			cout << 1 << endl;
			return 0;
		}
	}
	cout << -1 << endl;
	return 0;
}