#include<iostream>
#include<string>
#include<algorithm>

int main() {
	std::string password;
	std::cin >> password;

	for (int i = 0; i < password.length(); i++) {
		if (password[i] >= 'A' && password[i] <= 'Z') {
			password[i] += 32;
		}
		else {
			password[i] -= 32;
		}
	}

	std::cout << password << std::endl;
	return 0;
}