#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
using mint = atcoder::modint998244353;
using maxt = atcoder::modint1000000007;

int main() {
  int64_t N;
  cin >> N;
	cout << N;
	if(N != 0) {
	  cout << 0;
	}
	cout << endl;
}