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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

class Program
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());

        bool flag = Calq(n);

        if (flag) Console.WriteLine("Yes");
        else Console.WriteLine("No");
    }

    static bool Calq(int n)
    {
        bool flag = false;

        if (n < 4) return flag;
        else
        {
            for (int i = 0; i < 15; i++)
            {
                for (int j = 0; j < 26; j++)
                {
                    if (7 * i + 4 * j > 100) break;
                    else if (7 * i + 4 * j == n)
                    {
                        flag = true;
                        break;
                    }
                }
                if (flag == true) break;
            }
        }

        return flag;
    }
}