#include<iostream>
#include<string.h>
#include<math.h>
#include<cstdio>
using namespace std;
typedef long long LL;
double pd(double x){
	return x*x*x;
}
int main(){
	LL n;
	scanf("%lld",&n); 
	double l=1;
	double r=n;
	while(r-l>1e-2){
		double mid=(l+r)/2.0;
		if(pd(mid)<n){
			l=mid;
		}
		if(pd(mid)>=n){
			r=mid;
		}
	}
	printf("%.lf",l);
	return 0;
}