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: Accepted)

function main(input){
  const args = input.split(' ');
  const R = parseInt(args[0], 10),
        G = parseInt(args[1], 10),
        B = parseInt(args[2], 10),
        N = parseInt(args[3], 10);
  
  var s = 0;
  var k = 0;
  for (var i = 0; i <= (N / R | 0); ++i){
    for (var j = 0; j <= (N / G | 0); ++j){
      k = ((N - i*R - j*G) / B) | 0;
      if (k >= 0 && i*R + j*G + k*B == N) ++s;
    }
  }
  console.log(s);
}

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