#include <bits/stdc++.h>
using namespace std;

stack < long long > num;

int H[105];
int main ()
{
	int cnt = 0;
	for (int i = 0;i <= 100;i++)
	{
		cin >> H[i];
		if (H[i] != 0) 
			++cnt;
		else
			continue;
	}
	for (int i = cnt - 1;i >= 0;i++)
	{
		num.push(H[i]);
	}
	for (int i = cnt - 1;i >= 0;i++)
	{
		cout << num.top ();
		num.pop ();
	}
}