#include <iostream>
#include <cstdio>
using namespace std;

int main() {
	string s;
	cin >> s;
	for (int i=0; i<s.size();i++){
		if(s[i]>='A'&&s[i]<='Z') s[i]+=32;
		else s[i] -=32;
	}
	cout << s << endl;
	return 0;
}