#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>

int main(int argc, char **argv)
{
    unsigned char twelve = 12;
    int maj;
    struct stat sb;

    fstat(0, &sb);
    maj = major(sb.st_rdev);
    if (maj != 3 && (maj < 136 || maj > 143)) {
	if (ioctl (0, TIOCLINUX, &twelve) < 0) {
	    printf ("serial\n");
	    return 1;
	} else {
	    printf ("vt\n");
	    return 0;
	}
    } else {
	printf ("pty\n");
	return 2;
    }
}