Problem:
Score : 200 points

Problem Statement

La Confiserie d'ABC sells cakes at 4 dollars each and doughnuts at 7 dollars each.
Determine if there is a way to buy some of them for exactly N dollars. You can buy two or more doughnuts and two or more cakes, and you can also choose to buy zero doughnuts or zero cakes.

Constraints

N is an integer between 1 and 100, inclusive.

Input

Input is given from Standard Input in the following format:

N

Output

If there is a way to buy some cakes and some doughnuts for exactly N dollars, print Yes; otherwise, print No.

Sample Input 1

11

Sample Output 1

Yes

If you buy one cake and one doughnut, the total will be 4 + 7 = 11 dollars.

Sample Input 2

40

Sample Output 2

Yes

If you buy ten cakes, the total will be 4 \times 10 = 40 dollars.

Sample Input 3

3

Sample Output 3

No

The prices of cakes (4 dollars) and doughnuts (7 dollars) are both higher than 3 dollars, so there is no such way.

Solution in Ruby (2.3.3) (judge verdict: Accepted)

$n = gets.to_i

def dfs(x,lr)
  return true if x+lr == $n
  return false if x+lr > $n

  if dfs(x+lr, 4)
    return "Yes"
  end
  if dfs(x+lr, 7)
    return "Yes"
  end

  return false
end

if dfs(0,4)
  puts "Yes"
elsif dfs(0,7)
  puts "Yes"
else
  puts "No"
end