You are given a string $S$ consisting of lowercase English letters. Find the character that appears most frequently in $S$. If multiple such characters exist, report the one that comes earliest in alphabetical order.

The input is given from Standard Input in the following format:

```
$S$
```

Among the characters that appear most frequently in $S$, print the one that comes earliest in alphabetical order.

-   $1 \leq |S| \leq 1000$ ($|S|$ is the length of the string $S$.)
-   Each character in $S$ is a lowercase English letter.

a

In frequency, the letter e appears twice, which is more than any other character, so you should print e.In atcoder, each of the letters a, t, c, o, d, e, and r appears once, so you should print the earliest in alphabetical order, which is a.