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 Ruby (2.3.3) (judge verdict: Runtime Error)

#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int main(void)
{
  ll R,G,B,N;
  cin >>R>>G>>B>>N;
  ll ans=0;
  for(ll r=0;r*R<N;r++) {
    for(ll g=0;g*G<N;g++) {
      ll bn=N-r*R-g*G;
      if(bn>=0&&bn<=N&&bn%B==0){
        ans++;
      }
    }
  }
  cout << ans << endl;
}