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

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

    for(int i=0;i!=S.size();i++) {
        if(isupper(S[i])) ans.push_back(tolower(S[i]));
        else ans.push_back(toupper(S[i]));
    }
    cout << ans << endl;

    return 0;
}