#include    <stdio.h>
#include    <ctype.h>

int main(void)
{
    char    c;

    while ((c = getchar()) != EOF) {
        if (c == '\n') {
            break;
        } else if (islower(c)) {
            putchar(toupper(c));
        } else {
            putchar(tolower(c));
        }
    }
    putchar('\n');

    return 0;
}