include <bits/stdc++.h>

define ll long long int

define ld long double

using namespace std; int main(){

ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll n, m, k = 1;
cin>>n;
m = n;
while(n == m){
    m >>= k;
    m <<= k;
    k++;
}
cout<<m;

} //TECHNOBLADE NEVER DIES