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 <iostream>
#include <cstdio>
#include <cctype>
using namespace std;

int main()
{
	// ?????°??£?¨?
	char ch;

	while (1)
	{
		// ????????\???
		cin >> ch;
		// ???????????´?????\?????????
		if (ch == '\n')
		{
			break;
		}

		// ??§???????°????????????????
		if (0 != islower(ch))
		{ // ?°????????????´???
			// ?°????????????§???????????????
			ch = toupper(ch);
			// ???????????????
			cout << ch;
		}
		else if (0 != isupper(ch))
		{ // ??§???????????´???
			// ??§??????????°????????????????
			ch = tolower(ch);
			// ???????????????
			cout << ch;
		}
		else
		{
			// ???????????????
			cout << ch;
		}
	}
	// ??????
	cout << endl;
	return 0;
}