#include <iostream>
#include<string>

using namespace std;

int main() {
	string s;
	cin >> s;
	for (int i = 0; i < s.size(); i++)
	{
		char c = s[i];
		if (c >= 'a' && c <= 'z') c = c - 'a' + 'A';
		else c = c + 'a' - 'A';
		cout << c;
	}

	cout << endl;
}