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 Program
{
	static void Main(string[] args)
	{
       string[] input = Console.ReadLine().Split(' ');
       int R = int.Parse(input[0]);
       int G = int.Parse(input[1]);
       int B = int.Parse(input[2]);
       int N = int.Parse(input[3]);
      
       int result = 0;
       for(int i = 0; i <= 3000; i++)
       {
         for(int j = 0; j <= 3000; j++)
         {
             int rg = i*R + j*G;
             if(N >= rg && (N-rg) % B == 0) result++;
         }
       }
      
       Console.WriteLine("{0}", result);
	}
}