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;
using System.Collections.Generic;
using System.Linq;
class Program{
static void Main(string[] args){

var RGBN = Console.ReadLine().Split().Select(x => int.Parse(x)).ToList();
var R=RGBN[0];
var G=RGBN[1];
var B=RGBN[2];
var N=RGBN[3];
int cnt=0;
for(int i=0;i<=N/R;i++){
    if(R*i==N){cnt+=1;break;}
    for(int j=0;j<=N/G;j++){
        if(R*i+G*j==N){cnt+=1;break;}
        for(int k=0;k<=N/B;k++){
            if(R*i+G*j+B*k==N){cnt+=1;break;}
        }}}
Console.WriteLine(cnt);

}
}