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 JAVA (judge verdict: Accepted)

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
// 標準入力からデータを読み込む準備
try (Scanner sc = new Scanner(System.in)) {
String line = sc.nextLine();
String answer = "";
int length = line.length();
for (int i = 0; i < length; i++) {
char ch = line.charAt(i); // 文字列(line)からi番目の文字を取り出す
// Character.isLowerCase で小文字かどうか判断可能
// Character.toUpperCase, Character.toLowerCase で変換
// 記号は上記メソッドで変換にかけても変化しない
if(Character.isLowerCase(line.charAt(i))){
     answer += Character.toUpperCase(line.charAt(i));
} else {
     answer += Character.toLowerCase(line.charAt(i));
}
}
System.out.println(answer);
}
}
}