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;
using System.Collections.Generic;

public class CSharp
{
    public static void Main()
    {
        Kyopuro chokudai = new Kyopuro();
        chokudai.AtCoder();
    }
}

public class Kyopuro
{
    public void AtCoder()
    {
        string[] input;
        input = Console.ReadLine().Split(' ');

        int a, b, c, n;
        a = int.Parse(input[0]);
        b = int.Parse(input[1]);
        c = int.Parse(input[2]);
        n = int.Parse(input[3]);

        int ans = 0;
        int x = 0;

        for(int i=0; i<=n; i++)
        {
            for(int j=0; j<=n; j++)
            {
                x = n - a * i - b * j;
                if (x >= 0 && x % c == 0) ans++;
            }
        }

        Console.WriteLine(ans);
    }
    public static void DebugWL(object x) { System.Diagnostics.Debug.WriteLine(x); }
}