求助！！！！！！！！！！！

#include<bits/stdc++.h>
using namespace std;
int main(){
    long long begin,end,num = 0;
    cin >> begin >> end;
    for(long long i = begin;i <= end;i++){
        if(i % 4 == 0 || i % 400 == 0)num += i;
    }
    cout << num;
    return 0;
}