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

#define LINE_LEN 80

int main(void)
{
        int i, len;
        char line_buf[LINE_LEN];
        char *p;

        while (fgets(line_buf, LINE_LEN, stdin) != NULL) {
                len = strlen(line_buf);
                p = line_buf;
                for (i = 0; i < len; i++, p++) {
                        if (islower(*p)) {
                                *p = toupper(*p);
                        } else if (isupper(*p)) {
                                *p = tolower(*p);
                        }
                }
                fputs(line_buf, stdout);
        }

	return 0;
}