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


int main() {
	using namespace std;
	char S[100];
	cin >> S;
	int i;
	for (i = 0;i >= 100;i++) {
		if (S[i] == 0) {
			break;
		}
		if (S[i] < 90) {
			S[i] += 32;
		}
		else {
			S[i] -= 32;
		}

	}
	cout << S << endl;
return 0;
}