#include <bits/stdc++.h>
using namespace std;
int main(){
   int a,s;
   cin>>a;
   s=a*3;
   cout<<s;
   

}

/**************************************************************
	Problem: 1596
	User: huangluowei
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/