#include <iostream>

using namespace std;

int main(int argc, const char *argv[])
{
	string S;
	cin >> S;
	for (auto &&c : S) {
		if ('a' <= c && c <= 'z')
			cout << (char)('A' + (c - 'a'));
		else
			cout << (char)('a' + (c - 'A'));
	}
	cout << endl;
	return 0;
}