#include <bits/stdc++.h>
using namespace std;
int main(){

	int i,n;
	cin>>i;
	n=i*3;
	cout<<n;
	
	return 0;
}
/**************************************************************
	Problem: 1596
	User: huangyaojie3
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/