You are given a string of length N . Find the most repeated character in the string. If many characters appear same number of times find the smallest one .
Input format
First line contain string S of length N.
Output format
Print the most repeated letter in S.
Input Constraints
1≤N≤10
Frequency of both 'a' and 'z' is 2 but since 'a' is lexographically smaller than 'z' so the answer is 'a'.