require "ext"
local cave = {}
local lowest = 0
for line in io.lines() do
	print("line:",line)
	local cursor = nil
	for pair in line:gmatch("([0-9,]+)") do
		local col,row  = pair:match("(%d+),(%d+)")
		col,row = tonumber(col),tonumber(row)
		if cursor then
			for rown = math.min(cursor[1],row), math.max(cursor[1],row) do
				for coln = math.min(cursor[2],col), math.max(cursor[2],col) do
					cave[rown] = cave[rown] or {}
					printf("Setting %d %d to true",rown,coln)
					cave[rown][coln] = true
				end
			end
		end
		lowest = math.max(row,lowest)
		cursor = {row,col}
	end
end

local sand = {}
function print_puzzle()
	for row = 0, 11 do
		for col = 480,520 do
			local data = cave[row] and cave[row][col]
			if data == "s" then
				io.write("O")
			elseif data then
				io.write("#")
			else
				io.write(".")
			end
		end
		io.write("\n")
	end
	for _,row in pairs(cave) do
		for _,col in pairs(row) do
		end
	end
end
print_puzzle()
print("lowest:",lowest)
local floor = lowest + 2
cave[floor] = {}
for i = -(500 - floor), (500 + floor) do
	cave[floor][i] = true
end

local sandpoint = {0,500}
local movement = {
	{1,0},
	{1,-1},
	{1,1}
}
local x = 0
while true do
	for k,v in pairs(sandpoint) do
		sand[k] = v
	end
	local could_move = false
	repeat
		could_move = false
		for _,move in ipairs(movement) do
			local drow, dcol = sand[1] + move[1], sand[2] + move[2]
			if not cave[drow] or cave[drow][dcol] == nil then
				could_move = true
				sand[1] = drow
				sand[2] = dcol
				break
			end
		end
	until not could_move or sand[1] == floor 
	if not could_move then
		cave[sand[1]] = cave[sand[1]] or {}
		cave[sand[1]][sand[2]] = "s"
	end
	if sand[1] == 0 then
		print("sand stopped falling")
		break
	end
	x = x + 1
end
print_puzzle()
print(x + 1)