#include <iostream>
#include <string>

int main() {
    std::string s;
    
    std::cin >> s;
    
    for (int i = 0; i < s.size(); i++) {
        if (s[i] <= 90 && s[i] >= 65) s[i] += 32;
        else if (s[i] <= 122 && s[i] >= 97) s[i] -= 32; 
    } 
    
    std::cout << s << std::endl;
	
	return 0;
}