#include <bits/stdc++.h>
using namespace std;
int main(){
	int n,r;
	cin>>n;
	r=n*3;
	printf("%d",r);
    }
/**************************************************************
	Problem: 1596
	User: tonghuawei
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/