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;

class Program
{
  static void Main(string[] args)
  {
    string s = Console.ReadLine();
    string[] s2 = s.Split(' ');

    int r = int.Parse(s2[0]);
    int g = int.Parse(s2[1]);
    int b = int.Parse(s2[2]);
    int n = int.Parse(s2[3]);

    int max = r;
    if (max < g) max = g;
    if (max < b) max = b;

    int m = (int)(Math.Floor((double)n / max)) + 1;

    int count = 0;

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

    Console.WriteLine(count);
  }
}