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++14 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <iostream>
using namespace std;

int main () {
    int R, G, B, N;
    int ans = 0;
    cin >> R >> G >> B >> N;
    for (int i = 0; i <= N; i++) {
        if (R * i <= N) {
            for (int j = 0; j <= N; j++) {
                if (R * i + G * j <=N) {
                    for (int k = 0; k <= N; k++) {
                        if (R * i + G * j + B * k == N) {
                            ans++;
                        }
                    }
                }
            }
        }
    }
    cout << ans << endl;

    return 0;
}