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: Time Limit Exceeded)

using System;
using System.Linq;
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 rCount = N / R;
        int gCount = N / G;
        int bCount = N / B;
        int ans = 0;
        for (int i = 0; i <= rCount; i++)
            for (int j = 0; j <= gCount; j++)
                for (int k = 0; k <= bCount; k++)
                {
                    if (R * i + G * j + B * k == N)
                        ans++;
                }
        Console.WriteLine(ans);
    }
}