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