#include<bits/stdc++.h>
using namespace std;
int f(int n){
	int r=0;
	if(n==1) r=1;
	else r=f(n-1)+n-1;
	return r;
}
int main(){
	int s=0;
	for(int i=1;s<=5000;i++){
		s=0;
		for(int j=1;j<=i;j++){
			s=s+f(j);
		}
	}
	cout<<s;
	return 0;
}
/**************************************************************
	Problem: 1146
	User: panyuchen
	Language: C++
	Result: Accepted
	Time:4 ms
	Memory:2072 kb
****************************************************************/