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

stone_blocks(H) ->
    {_, Blocks} = lists:foldl(fun(Hi, {Stack, BlocksCount}) ->
        Stack1 = pop_while_greater(Stack, Hi),
        case Stack1 of
            [Hi | _] -> {Stack1, BlocksCount};
            _ -> {[Hi | Stack1], BlocksCount + 1}
        end
    end, {[], 0}, H),
    Blocks.

pop_while_greater([Top | Rest], Hi) when Top > Hi ->
    pop_while_greater(Rest, Hi);
pop_while_greater(Stack, _Hi) ->
    Stack.