#include<bits/stdc++.h>
using namespace std;
int main(){
  int i,k=0;
  char s[100],w[100],r[100]={'\0'};
  gets(s);
  for(i=0;i<strlen(s);i++){
  if(s[i]!=' '){
  w[k]=s[i];
  k++;
  if(s[i+1]==' '||s[i+1]=='\0'){
  w[k]='\0';
  if(strlen(w)>strlen(r)) strcpy(r,w);
  k=0;
  } 
  } 
  }
  cout<<r<<endl;
return 0;
}
/**************************************************************
	Problem: 1107
	User: wtq001
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2076 kb
****************************************************************/