#include <stdio.h>

#include <string.h>

void longword(char str[],char word[]){
    int len = 0;
    int i = 0, j = 0;
    while(str[i] != '\0'){
        j=i;
        while(str[j]!=' '&&str[j]!='\0' ){
            j++;
        }
        len = j-i;
        if(len > strlen(word)){

            strncpy(word,str+i,len);
        }
        i=j+1; 
    }

}

int main(){
    char str[256];
    gets(str);//scanf遇到空格会中断
    char word[256]={0};//用于存储最长的单词
    longword(str,word);
    printf("%s",word);
    return 0;

}