#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;

int max(int a, int b) {
	int x = (a > b) ? a : b;
	return x;
}

int min(int a, int b) {
	int x = (a < b) ? a : b;
	return x;
}

int main() {
	string s;
	cin >> s;
	if(s!="0")cout << s;
	cout << 0 << endl;

	return 0;
}