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Description

You are in the Hello ACM competition. But you found that you can only come up with a brute force.

Your brute force code is:

#include<bits/stdc++.h>
using namespace std;
int main(){
    unsigned long long ans=0;
    for(int x=1;x<=10000000;++x){
        ans+=x;
        for(int y=1;y<=x;++y){
            ans-=y;
            for(int z=1;z<=y;++z){
                ans+=z;
                for(int w=1;w<=z;++w){
                    ans-=w;
                    ++ans;
                }
            }
        }
    }
    printf("%llu\n", ans);
    return 0;
}

It is absolutely impossible to run out the answer. But you may calculate it by hand, and output it directedly. Only through this way can you accept this problem and get rk1.

Format

Only a single number. The output of the brute force code.

Samples

The example is for illustration of the format only; it may be incorrect.

114514