#include<iostream>

using namespace std;

int main(void)
{
    int n;
    cin>>n;
    
    cout<<n*3<<endl;
	return 0;
}
/**************************************************************
	Problem: 1596
	User: 231308061
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/