#include <iostream>
using namespace std;

int main()
{
	char S[101];
	cin >> S;

	for(int i = 0; S[i]; ++i)
	{
		if(('a' <= S[i]) && (S[i] <= 'z'))
		{
			S[i] = ('A' + (S[i] - 'a'));
		}
		else
		{
			S[i] = ('a' + (S[i] - 'A'));
		}
	}

	cout << S << endl;
	return 0;
}