#include<bits/stdc++.h>
using namespace std;
int main(){
	string s,a,mx="";
	getline(cin,s);
	for(int i=0;i<s.size();i++){
		if(s[i]!=' ') a+=s[i];
		else if(a.size()>mx.size()){
			mx="";
		 	mx=a;
		 	a="";}
	}
	cout<<mx;
	return 0;
}
/**************************************************************
	Problem: 1107
	User: panyuchen
	Language: C++
	Result: Wrong Answer
****************************************************************/