#include <iostream>
#include <string>
using namespace std;
int main() {
    string b, s;
    int i;
    cin >> s;
    for (i = 0; i < s.length(); i++) {
    	if (s[i] < 91) {b += s[i] + 32;}
    	else {b += s[i] - 32;}
    }
    cout << b << endl;
    return 0;
}