NOTE : USE C LANGUANGE, USE SORTING, DONT USE STDLIB.H LIBRARY, DONT USE VOID MAIN

The switch of every keys in Jojos mechanical keyboard are weird. Characters are typed more times than the keys are pressed. Given S, determine the shortest ordering of keypress Jojo did.

Format Input

The only line of input contains S, the string of typed characters.

Format Output

The output of this problem will be the order of keypresses.

Constraints

1 |S| 105

Sample Input (standard input)

Bllueeee Swiitchesss

Sample Output (standard output)

Blue Switches