1ok puts 2ok printf 3ok puts_nonl 4ok putchar 5ok getchar 6ok strlen 7ok strcmp 8ok gets 9ok isspace 10ok isdigit 11ok strtol 12ok strcpy 13ok memmove 14ok strcat 15ok toupper 16ok tolower 17ok isprint 18ok memcpy 19ok memset 20ok atoi 21