#!usr/bin/env js

var url = readline();
var get = "";
<<<<<<< HEAD
if (url.match(/[^\].+[^\]+\s/){
=======
if (url.match(/+[^\][^\]+[^\]\s/)){
>>>>>>> 27137d83aa7d2b8d01d8d0dd4110c1b03158c094
get = RegExp.$1;
}
print(get);