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: Accepted)

#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define vecll vector<long long>
#define vec2ll vector<vector<long long>>
#define vecbool vector<bool>
#define vecpairll vector<pair<long long,long long>>
#define forll(s,a,b) for(long long s = a;s < b;s++)
#define forllde(s,a) for(long long s = a;s > 0;s--)


int main()
{
  ll r, g, b, n, c=0, t;
  cin >> r >> g >> b >> n;
  for(int i=0; i*r<=n; i++){
	for(int j=0; j*g<=n; j++){
	  t = n - i * r - j * g;
	  if(t % b == 0 && t >= 0)
		c++;
	}
  }
  cout << c << endl;
}