#include <bits/stdc++.h>
using namespace std;

int main()
{
	string S;
	cin >> S;

	string ans;
	for( int i = 0; i < S.size(); i++ ) {
		if( isupper( S[i] ) ) ans += tolower( S[i] );
		else ans += toupper( S[i] );
	}

	cout << ans << endl;
}