#include<bits/stdc++.h>
using namespace std;
int n;
int main(){
   cin>>n;
   cout<<3*n;
   return 0;
   if(n==n){
   }
}

/**************************************************************
	Problem: 1596
	User: wangyichen2
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/