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

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

    for(int i = 0; i < S.size(); i++){
        if(isupper(S.at(i))){
            S.at(i) = tolower(S.at(i));
        }else{
            S.at(i) = toupper(S.at(i));
        }
    }
    cout << S << endl;
    return 0;
}