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 JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

'use strict'
function Main(input){
  input=input.trim().split(/\s+/).map(x=>x-0);
  var R=input[0],G=input[1],B=input[2],N=input[3];
  function rg(M){
    var counter=0;
    var r=Math.floor(M/R);
    var g=0;
    while(r>=0){
      while(r*R+g*G<M)g++;
      if(r*R+g*G===M)counter++;
      r--;
    }
    return counter;
  }
  var b=0;
  var ans=0;
  while(b*B<=N){
    ans+=rg(N-b*B);
  }
  console.log(ans);
}

Main(require('fs').readFileSync('/dev/stdin','utf8'));