local read, write = io.read, io.write
local b=2
local n, sum
n = 1
while n <= 100 do
	sum = 0
	b = 2
	while b*b <= n do
		if n%b == 0 then 
			sum = sum + b
			if b*b == n then
			else
				sum = sum + (n/b)
			end
		end
		b = b+1
	end

	if sum == n then write("yes")
	else write("no")
	end
	n = n + 1
end