(* Get the i^th entry in the list, and convert it to an Int64. *) let nth l i = (Int64.of_string (List.nth l i));; try while true; do let line = read_line () in let tokens = Str.split (Str.regexp " ") line in let a = (nth tokens 0) in let b = (nth tokens 1) in let diff = Int64.abs (Int64.sub a b) in begin Printf.printf "%Ld\n" diff end; done; with End_of_file -> ();;