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

int main()
{
    char password[200];
    cin >> password;
    for (int i = 0; password[i] != '\0'; ++i){
        if (65 <= password[i] && password[i] <= 90){
            password[i] += 32;
        }else{
            password[i] -= 32;
        }
    }

    cout << password << endl;
    return 0;
}