#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdbool.h>
int main(int argc, char *argv[])
{
    bool upper = ((char)getc(stdin) == 'u');
    while (true) {
        int c = getc(stdin);
        if (c == EOF) {
            break;
        }
        if (upper)
            putc((char)toupper(c), stdout);
        else
            putc((char)(tolower(c)), stdout);



    }
    return EXIT_SUCCESS;
}