#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <err.h>

int
main(int argc, char *argv[])
{
   if (argc < 2)
      errx(EXIT_FAILURE, "usage: %s hex ... < input > output", argv[0]);

   uint8_t buf[4096];
   for (size_t ret, c = 0; (ret = fread(buf, 1, sizeof(buf), stdin)) > 0;) {
      for (size_t i = 0; i < ret; ++i, c = (c + 1) % (argc - 1))
          buf[i] ^= strtoull(argv[c + 1], 0, 16);
      fwrite(buf, 1, ret, stdout);
   }

   return EXIT_SUCCESS;
}