#include<bits/stdc++.h>
using namespace std;
int main() {
	int n,s;
	scanf("%d",&n);
	s=n*3;
	printf("%d",s);
    return 0;
}

/**************************************************************
	Problem: 1596
	User: huangcanwu
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/