#include<bits/stdc++.h> using namespace std; int main(){ long long n,cnt=0,b=0; cin>>n; for(int i=1;i<=n;i++){ cnt+=i*i; } cout<<cnt; return 0; } /************************************************************** Problem: 1553 User: xuanhua Language: C++ Result: Accepted Time:42 ms Memory:2072 kb ****************************************************************/