#include <bits/stdc++.h>
using namespace std;
string s;
int main() {
	cin >> s;
	for(int i = 0; i < s.size(); i++) {
		if(isupper(s[i])) s[i] = tolower(s[i]);
		else s[i] = toupper(s[i]);
	}
	cout << s << endl;
	return 0;
}