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

main([N])-> push(list_to_integer(atom_to_list(N)),[]).

push(0,_)->0;
push(1,L)->io:format("~s~n",[L ++ "*"]), pop(L ++ "*");
push(N,L)->io:format("~s~n",[L ++ "*"]), push(N - 1, L ++ "*").

pop("*")-> 0;
pop([_|L])-> io:format("~s~n",[L]), pop(L).