#include <bits/stdc++.h>
using namespace std;
int main (){
	
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	char s;
	vector<char> C;
	while( cin >> s ){
		C.push_back(s);
	}
	string S;
	for( char x : C ){
		S += ( x == toupper(x) ? tolower(x) : toupper(x) );
	}
	cout << S << endl;
	return 0;
}