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 C (judge verdict: Time Limit Exceeded)

#include <stdio.h>

int main()
{
    char ch;
    
    while(scanf("%s", ch) != EOF){
        if (ch == '\n') break;
        else if ('a' <= ch && ch <= 'z'){ch = toupper(ch); printf("%s", ch);}
        else if ('A' <= ch && ch <= 'Z'){ch = tolower(ch); printf("%s", ch);}
    }
    return 0;
}