#include<iostream>
#include<string>
using namespace std;
int main() {
	string S;
	cin >> S;
	int size = S.size();
	for (int i=0; i < size; i++) {
		if (S[i]>64 && S[i]<91 ) {
			S[i] += 32;
		}
		else if (S[i] > 96 && S[i] < 123) {
			S[i] -= 32;
		}
	}
	cout << S << endl;
}