-module(main).
-export([main/1]).

main( [ A | [ B |[]]]) ->
   io:fwrite("~p~n",[ack(toi(A),toi(B))]).

toi(E) -> element(1,string:to_integer(E)).

ack(0,N) -> N + 1;
ack(M,0) -> ack(M-1, 1);
ack(M,N) -> ack(M-1,ack(M,N-1)).