s = gets.to_i

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

while 0
	over = false
	for k in start..10
		fizz = (n + step) / 3 - n / 3
		buzz = (n + step) / 5 - n / 5
		fizz_buzz = (n + step) / 15 - n /15
		fizz -= fizz_buzz
		buzz -= fizz_buzz
		
		addition = (k == 10 && k % 3 > 0 && k % 5 > 0 ? 1 : 0) +  
			digit * (step - fizz - buzz - fizz_buzz) +
			4 * (fizz + buzz) +
			8 * fizz_buzz
		
		if s <= addition
			stack << k-1
			over = true
			start = 1
			break
		else
			s -= addition
			n += step
			start = 2
		end
	end
	
	if over
		step /= 10
		break if step == 0
	else
		step *= 10
		digit += 1
	end
end

x = stack.join.to_i + 1
str = ""
while 0
	if x % 15 == 0
		str += "FizzBuzz"
	elsif x % 3 == 0
		str += "Fizz"
	elsif x % 5 == 0
		str += "Buzz"
	else
		str += x.to_s
	end
	break if str.size - s >=  20
	x += 1
end

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