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