#include <iostream>
using namespace std;

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

	for (int i = 0; i < (int)S.size(); i++) {
		if ('a' <= S[i] && S[i] <= 'z') S[i] -= 32;
		else S[i] += 32;
	}
	cout << S << endl;
}