#include <string>
#include <vector>

using namespace std;

int solution(int n) {
    int answer = 0;
    if(n%2==0){
        for(int i=0; i<=n; i+=2){
            answer += i*i;
        }
    }
    else{
        for(int i=1; i<=n; i+=2){
            answer += i;
        }
    }
    
    return answer;
}