A billboard display string is made of English letters (upper or lower case), digits, and the punctuation characters ., -, and _. To create a mirrored effect, only the letters are reversed among themselves; every non-letter character stays exactly where it is.
Concretely, read the letters left to right, reverse that sequence, and place them back into the positions that originally held letters, in order. Non-letter positions are untouched.
Input format
Line 1: a non-empty string made of the characters a-z, A-Z, 0-9, ., -, and _.
Output format
A single line: the transformed string.
Constraints
- 1 <= length of the string <= 100000
- The string contains no spaces.