#include <iostream>
using namespace std;

char str[105] = {};

int main() {
    int i = 0;

    cin >> str;
    while(str[i]) {
        //0x5a("Z")で判別
        if(str[i] <= 0x5a) str[i] += 0x20;
        else if(str[i] > 0x5a) str[i] -= 0x20;
        i++;
    }
    cout << str << endl;
    return 0;
}