Problem:
Score : 200 points

Problem Statement

Snuke has come to a store that sells boxes containing balls. The store sells the following three kinds of boxes:

Red boxes, each containing R red balls

Green boxes, each containing G green balls

Blue boxes, each containing B blue balls

Snuke wants to get a total of exactly N balls by buying r red boxes, g green boxes and b blue boxes.
How many triples of non-negative integers (r,g,b) achieve this?

Constraints

All values in input are integers.

1 \leq R,G,B,N \leq 3000

Input

Input is given from Standard Input in the following format:

R G B N

Output

Print the answer.

Sample Input 1

1 2 3 4

Sample Output 1

4

Four triples achieve the objective, as follows:

(4,0,0)

(2,1,0)

(1,0,1)

(0,2,0)

Sample Input 2

13 1 4 3000

Sample Output 2

87058

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

using System;

class B
{
	static void Main()
	{
		var h = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);

		var c = 0;
		var rM = h[3] / h[0];
		for (int r = 0; r <= rM; r++)
		{
			var n2 = h[3] - r * h[0];
			var gM = n2 / h[1];
			for (int g = 0; g <= gM; g++)
			{
				var n3 = n2 - g * h[1];
				if (n3 % h[2] == 0) c++;
			}
		}
		Console.WriteLine(c);
	}
}