{
  let word = Sys.argv.(1)
}
rule scan c = parse
| ['a'-'z' 'A'-'Z']+ as w
{ scan (if word = w then c+1 else c) lexbuf }
|_
{ scan c lexbuf }
| eof {c}
{
let c = open_in Sys.argv.(2)
let n = scan 0 (Lexing.from_channel c)
let () = Printf.printf "%d occurrence(s)\n" n
}