#include<iostream>
using namespace std;
int main(void)
{
	int i;
	char s[105];

	cin >> s;
	
	for (i = 0; s[i] != '\0'; i++) {
		if (s[i] >= 'A'&&s[i] <= 'Z')
			s[i] = s[i] + 'a' - 'A';
		else if (s[i] >= 'a'&&s[i] <= 'z')
			s[i] = s[i] + 'A' - 'a';
	}
	cout << s << endl;

	return 0;
}