#include <iostream>
#include <string>
using namespace std;

int main(void){
//input
	string str;
	cin >> str;
//calc
	for(int i=0;i<str.size();i++){
		if(str[i] >= 'a' && str[i] <= 'z'){
			str[i] = str[i] - 32;
		}else if(str[i] >= 'A' && str[i] <= 'Z'){
			str[i] = str[i] + 32;
		}
	}
//output
	cout << str << endl;
}