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: Wrong Answer)

public class Hello{
    public static void Main(){
        // Your code here!
        int cnt = 0;
        var rgbn = System.Console.ReadLine().Split();
        var R = int.Parse(rgbn[0]);
        var B = int.Parse(rgbn[1]);
        var G = int.Parse(rgbn[2]);
        var N = int.Parse(rgbn[3]);
        for(var r = 0;r < N/R;r++){
            for(var g = 0;g < (N-r*R)/G;g++){
                var m = N - r*R - g*G;
                if(m == 0 || (m % B == 0 && m >= B)){
                    cnt++;
                }
            }
        }
        System.Console.WriteLine(cnt);
    }
}