Problem:
Toggling Cases

Write a program which converts uppercase/lowercase letters to lowercase/uppercase for a given string.

Input

A string is given in a line.

Output

Print the converted string in a line. Note that you do not need to convert any characters other than alphabetical letters.

Constraints

The length of the input string < 1200

Sample Input

fAIR, LATER, OCCASIONALLY CLOUDY.

Sample Output

Fair, later, occasionally cloudy.

Solution in PHP (judge verdict: WA: Presentation Error)

<?php
$str = trim(fgets(STDIN));

if(strlen($str) > 1200){
  echo 'error';
}else{

  for($i = 0; $i < strlen($str); $i++) {
    dispKekka($str[$i]);
  }
}

function dispKekka($str){
    $kekka1 = ctype_upper($str);
    $kekka2 = ctype_lower($str);
    $result = "";
    if ($kekka1 == TRUE){
        $result = strtolower($str); // ?°????????????????

    }else{
        if ($kekka2 == TRUE){
            $result = strtoupper($str); // ??§???????????????

        }else{
          $result = $str;
        }
    }
    echo $result;
}

// echo "\n";

?>