import java.util.*;
public class Hello{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String word = sc.next(), maxWord = "", newWord = "";
int l = word.length(), i, j, max = 0;
for (i = 0; i < l; i++) {
newWord = word.substring(i);
for (j = i + 1; j < l; j++){
if (newWord.indexOf(word.charAt(j)) + i != j)
break;
}
if (j - i > max) {
max = j - i;
maxWord = word.substring(i, j);
}
}
int t=maxWord.length();
if(t>=3){
System.out.println(maxWord);
}
else{
System.out.println("-1");
}
}
}
0 Comments