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)

var lines = [];
var readline = require('readline');

var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
});

rl.on('line', function (x) {
    lines.push(x);
});

rl.on('close', function () {
    var R = Number(lines[0].split(" ")[0]);
    var G = Number(lines[0].split(" ")[1]);
    var B = Number(lines[0].split(" ")[2]);
    var N = Number(lines[0].split(" ")[3]);

    var ans = 0;
    for (var r = 0; r <= 3000; r++) {
        for (var g = 0; g <= 3000; g++) {
            var b = N - r * R - g * G;

            if (b < 0 || b % B !== 0) { continue; }
            ans++;
        }
    }

    console.log(ans);

});