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)

namespace diverta2019.B
{
    using System.Collections.Generic;
    using System.Linq;
    using static System.Console;
    public class Program
    {
        public static void Main(string[] args)
        {
            var l = ReadLineAsInts().ToList();
            var r = l[0];
            var g = l[1];
            var b = l[2];
            var n = l[3];

            WriteLine(Solve(r, g, b, n));
        }

        public static IEnumerable<int> ReadLineAsInts() => ReadLine().Split(' ').Select(x => int.Parse(x));

        public static int Solve(int R, int G, int B, int n)
        {
            var count = 0;

            for (int i = 0; ; i++)
            {
                if (i * R > n) break;

                for (int j = 0; ; j++)
                {
                    if (i * R + j * G > n) break;

                    if ((n - (i * R + j * G)) % B == 0) count++;
                }
            }


            return count;
        }
    }
}