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-mcs 6.8.0.105) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;
using System.IO;
using static System.Console;


namespace atcorder2
{
    class Program
    {
        public static long Read()
        {

            return long.Parse(Console.ReadLine());
        }

        public static long[] Reads()
        {

            return Console.ReadLine().Split().Select(long.Parse).ToArray();
        }

       
         public static long GCM(long x,long y)
        {
            if (x < y)  GCM(y, x);


            while (y > 0)
            {
                var z = y;
                y = x % y;
                x = z;
            }
            
            return x;
        }

        



        static void Main(string[] args)
        {
            var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);


            var rgbn = Reads();
            var r = rgbn[0];
            var g = rgbn[1];
            var b = rgbn[2];
            var n = rgbn[3];
            long ans = 0;
            for (int i = 0; i <= 3000; i++)
            {
                for (int j = 0; j <= 3000; j++)
                {
                    long c = n - i * r - j * g;
                    if (c % b == 0  && 0 <= c / b) ans++;
                }
            }
            WriteLine(ans); 




















            Console.Out.Flush();
        }
    }
}