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;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        var input = Console.ReadLine().Split().Select(int.Parse).ToArray();
        var r = input[0];
        var g = input[1];
        var b = input[2];
        var n = input[3];

        var ans = 0;

        for(var i = 0; i <= n; i++)
        {
            if ((r* i) > n)
            {
                break;
            }
            for (var j = 0; j <= n; j++)
            {
                if ((g * j) + (r * i) > n)
                {
                    break;
                }


                if ((n - (r * i + g * j)) % b == 0 )
                {
                    ans++;
                }

                    /*
                for (var k = 0; k <= n; k++)
                {
                    if ((r * i) + (g * j) + (b * k) > n)
                    {
                        break;
                    }

                    if (r * i + g * j + b * k == n)
                    {
                        ans++;
                    } 
                }
                */
            }
        }


        Console.WriteLine(ans);
    }
}