#include<bits/stdc++.h>
using namespace std;
int main()
{
	string s;
	bool y=false;
	cin>>s;
	int n;
	n=s.size();
	if(s[0]=='-') cout<<"-";
	for(int i=n-1;i>=0;i--)
	{
		if(s[i]!='-'&&s[i]!='0') cout<<s[i]-48;
	}
}