#include<bits/stdc++.h>
using namespace std;
int main()
{
	char s[256],b[256],a[256]={'\0'};
	int i,j=0;
	gets(s);
	for(i=0;i<strlen(s);i++){
		if(s[i]!=' '){
			b[j]=s[i];
			j++;
			if(s[i+1]==' '||s[i+1]=='\0'){
				b[j]='\0';
				if(strlen(b)>strlen(a)){
					strcpy(a,b);
				}j=0; 
			}
		}	
	}cout<<a; 
	return 0;
}
/**************************************************************
	Problem: 1107
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/