#include<iostream>
#include<string>
using namespace std;
int main()
{
	string s;
	cin >> s;
	int len = s.length();
	for (int i = 0; i < len; i++)
	{
		if (s[i] < 91)s[i] += 32;
		else s[i] -= 32;
	}
	cout << s << "\n";
	return 0;
}