fun count_flips: Int do
		var flips = 1
		var first = p[0]
		if p[first] != 0 then
			p.copy_to(0, pp.length, pp, 0)
			while pp[first] != 0 do
				flips += 1
				var lo = 1
				var hi = first - 1
				while lo < hi do
					var t = pp[lo]
					pp[lo] = pp[hi]
					pp[hi] = t
					lo += 1
					hi -= 1
				end
				var t = pp[first]
				pp[first] = first
				first = t
			end
		end
		return flips
	end