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

int main() {
    string s;
    cin>>s;
    int diff = 'a'-'A';
    for (char& c : s) {
        if ('A' <= c && c <= 'Z') c += diff;
        else c -= diff;
    }
    cout << s << endl;
    return 0;
}