#include <iostream>
using namespace std;
int main(void){
    // Your code here!
    
    string s;
    cin >> s;
    
    int sl = s.size();
    for(int i = 0; i < sl; i++) {
        if(s[i] <= 'Z')s[i] = s[i] + 32;
        else s[i] = s[i] - 32;
    }
    
    cout << s;
    
}