#include<iostream>
using namespace std;

int main(){

    int N, eat,x,y,z,sum;
    cin >> N;

    if((1 <= N) && (N <= 100)){
        eat = N;

        for(int i = 1; i <= 3; i++){
            x = N % 2;
            y = N - x;
            z = y / 2;
            sum = eat + z;
            N =z;
        }


        cout<< sum;
    }

    return 0;
}