s = gets.to_i

n = 0
step = 1
digit = 1
stack = []
start = 0

loop {
	over = false
	(start..9).each{|k|
		fizz = (n + step) / 3 - n / 3
		buzz = (n + step) / 5 - n / 5
		fizz_buzz = (n + step) / 15 - n / 15
		
		addition = digit * (step - fizz - buzz + fizz_buzz) + 4 * (fizz + buzz) 
		
		if s <= addition
			stack << k
			over = true
			start = 0
			break
		else
			s -= addition
			n += step
			start = 1
		end
	}
	
	if over
		step /= 10
		break if step == 0
	else
		step *= 10
		digit += 1
	end
}

x = stack.join.to_i + 1
str = ""
loop {
	str += 
		x % 15 == 0 ? "FizzBuzz" :
		x % 3 == 0 ? "Fizz" :
		x % 5 == 0 ? "Buzz" :
		x.to_s
	break if str.size - s >=  20
	x += 1
}

puts str[s-1..s+18]