#include <iostream>
#include <string>
using namespace std;

int main() {
    string a;
    getline(cin,a);
    for (int i = 0; i < a.length(); ++i) {
        if (a[i]>=65&&a[i]<=90) a[i]+=32;
        else if (a[i]>=97&&a[i]<=122) a[i]-=32;
    }
    cout<<a<<endl;
    return 0;
}
