#include<bits/stdc++.h>
using namespace std;
int main(){ 
	int a,z;
	cin>>a;
	z=a*3;
	cout<<z;	
}
/**************************************************************
	Problem: 1596
	User: sucongyi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/