#include <iostream>
#include <string>
using namespace std;
int main()
{
	string c, w;
	cin >> w;
	c.resize(w.size());
	for (int i = 0; i < w.size(); i++)
	{
		if (w[i] >= 'A' && w[i] <= 'Z')
		{
			c[i] = w[i] + 32;
		}
		else if (w[i] >= 'a' && w[i] <= 'z')
		{
			c[i] = w[i] - 32;
		}
	}
	cout << c << endl;
	return 0;
}