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;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp11
{
    class Class51
    {
        static void Main()
        {
            var I = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int r = I[0];
            int g = I[1];
            int b = I[2];
            int N = I[3];
            int count = 0;
            int sum;
            for(int i = 0; i*r<= N; i++)
            {
                for(int j = 0; r*i + g*j<=N; j++)
                {
                    if ((N - r * i - g * j) % b == 0)
                    {
                        count++;
                    }
                }
            }
            Console.WriteLine(count);
        }
    }
}