#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b;
	cin>>a;
	b=a*3;
	cout<<b;
}
/**************************************************************
	Problem: 1596
	User: zengyixuan
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/