#include <stdio.h>
#include <stdlib.h>
#include <locale>

int mystrlen(char *string);

int main(){
	//char string[] = "swallow up - If a person or thing is swallowed up by something, they disappear into it so that you cannot see them any more.";
	char string[1024];
	gets(string);
	char min_word[15];
	int step = 0;
	int word_begin = 0, word_end = 0, word_min = 15;
	for (int i = 0; i < strlen(string); i++){
		if (string[i] >= 'a' && string[i] <= 'z'){
			if (i > 0){
				if (string[i - 1] < 'a'){
					word_begin = i;
				}
			}
			else{
				word_begin = i;
			}
		}
		if (string[i] < 'a'){
			word_end = i - 1;
		}
		if (word_end > word_begin && word_end - word_begin <= word_min){
				word_min = word_end - word_begin;
				for (int it = 0; it < 15; it++){
					min_word[it] = ' ';
				}
				step = 0;
				for (int is = word_begin; is <= word_end; is++){
					min_word[step] = string[is];
					step++;
				}
			}
	}
	for (int it = 0; it < 15; it++){
		if (min_word[it] >= 'a' && min_word[it] <= 'z')
			printf("%c", min_word[it]);
	}
	printf("\n");
	return 0;
}