#include <cctype>
#include <iostream>

int main(int argc, char *argv[]) {
	std::string wrong_password;
	std::cin >> wrong_password;

	std::string valid_password;
	for (auto i = wrong_password.begin(); i != wrong_password.end(); i++) {
		char current(*i);
		if (std::isupper(current)) {
			valid_password += static_cast<char>(std::tolower(static_cast<unsigned char>(current)));	
		}
		if (std::islower(current)) {
			valid_password += static_cast<char>(std::toupper(static_cast<unsigned char>(current)));	
		}
	}
	std::cout << valid_password << std::endl;
	return 0;
}