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>
#include <cstdio>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <array>
#include <numeric>
#include <functional>
#include <list>
#include <queue>
#include <deque>
#include <algorithm>
#include <utility>
#include <complex>

using namespace std;

#define REP(i,m,n) for(int i=m;i<=(n);i++)
#define rep(i,n) REP(i,0,n)
#define ALL(x) (x).begin(),(x).end()

typedef long long ll;
typedef pair<int, int> pii;

int main(){

	int r,g,b,n;
	cin >> r >> b >> g >> n;
	int a1 = n/r, a2 = n/g, a3 = n/b;
	int ans = 0;
	int sum;
	rep(i, a1){
		rep(j, a2){
			rep(l, a3){
				sum = r*i + g*j + b*l;
				if(sum == n) ans++;
				if(sum > n) break;
			}
		}
	}
	cout << ans << endl;
	return 0;
}