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