#include<bits/stdc++.h>
using namespace std;
int main()
{
	int i,n=0;
	char a[256],s[256],d[256]={'\0'};
	gets(a);
	for(i=0;i<strlen(a);i++){
		if(a[i]!=' '){
			s[n]=a[i];
			n++;
			if(a[i+1]==' '||a[i+1]=='\0'){
				s[n]='\0';
				if(strlen(s)>strlen(d)){
					strcpy(d,s);
				}
				n=0;
			}
		}	
	}
	cout<<d;
	return 0;
}

/**************************************************************
	Problem: 1107
	User: zzz
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2076 kb
****************************************************************/