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 <bits/stdc++.h>
using namespace std;
#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)

//C++14 (GCC 5.4.1)
int main() {
    int R,G,B,N;
    cin >>R>>G>>B>>N;

    //-----------------------------------
    int Ans=0,N_r,N_g,N_b;
    rep(r,N+1){
        N_r=N-R*r;
        if(N_r<0)break;
        rep(g,N+1){
            N_g=N_r-g*G;
            if(N_g<0)break;
            rep(b,N+1){
                N_b=N_g-b*B;
                if(N_b==0){
                    Ans++;
                }else if(N<0){
                    break;
                }
            }
        }
    }

    cout << Ans <<endl;
    return (0);
}