#include <iostream>
#include <string>
#include <ctype.h>

using namespace std;

int main() {
	string str;

	cin >> str;

	int len = str.length();

	for (int i = 0;i < len; i++) {
		if (str[i] >= 'a' && str[i] <= 'z') {
			str[i] = toupper(str[i]);
		}
		else if (str[i] >= 'A' && str[i] <= 'Z') {
			str[i] = tolower(str[i]);
		}
	}

	cout << str << endl;

	return 0;
}