include <bits/stdc++.h>

using namespace std; int a; int main() { freopen("nhandoi.inp","r",stdin); freopen("nhandoi.out","w",stdout); cin>>a; cout<<2*a; return 0;

}

[user:\(None\)[

> [x^2][1]

$$

]1\(None\)xin chao ca nha]