#include <iostream>
#include <string>

int main(){
	std::string s;
	std::cin >> s;
	for (int i = 0; i < s.size(); ++i){
		if ('a' <= s[i] && s[i] <= 'z')s[i] -= ('a' - 'A');
		else s[i] += ('a' - 'A');
	}
	std::cout << s << std::endl;
	return 0;
}