#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a=3,b;
	cin>>n;
	b=a*n;
	cout<<b;
    return 0;
}
/**************************************************************
	Problem: 1596
	User: caiqiaoxi
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/