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>
#include <ctype.h>

int main()
{
 char str[1200];
 char c;
 int i=0;
 while(1)
 {
  scanf("%c",&c);
  if(c=="")
   break;
  else
  {
   if(isupper(c))
    str[i]=tolower(c);
   else
   {
    if(islower(c))
     str[i]=toupper;
   }
  }
  i++;
 }
}