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

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

    for(int i=0; i<(int)s.length(); i++){
        if(islower(s[i])) s[i] = toupper(s[i]);
        else s[i] = tolower(s[i]);
    }

    cout << endl;
    return 0;
}