#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)

using namespace std;

typedef long long int lli;

int main() {
    string s;
    cin >> s;
    for (auto &c : s) {
        if ('a' <= c && c <= 'z') c -= 32;
        else if ('A' <= c && c <= 'Z') c += 32;
    }
    cout << s << endl;
    return 0;
}