-module(fib).

fib(Term) ->
    fib(Term, 1, 0).

fib(0, _Val, Prev) ->
    Prev;
fib(1, Val, _Prev) ->
    Val;
fib(Term, Val, Prev) ->
    fib(Term - 1, Val + Prev, Val).

main(_) ->
    N = 10,
    io:format("fib(~w) = ~w~n", [N, fib(N)]).