#include <iostream>
using namespace std;
char *switch_case(char *str) {
for (char *now = str; *now != '\0'; ++now) {
if (('A' <= *now && *now <= 'Z') ||
('a' <= *now && *now <= 'z')) {
*now = (char) (*now ^ 32);
}
}
return str;
}
int main(int argc, char *argv[]) {
cout << switch_case(argv[1]) << endl;
}
// ./xxx.exe khfe546FTYJ
// > KHFE546ftyj