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: Time Limit Exceeded)

input=gets.chomp.split()
a=input[0].to_i
b=input[1].to_i
c=input[2].to_i
n=input[3].to_i

count=0
sum=0
for i in 0..(n/c) do
  for j in 0..(n/b) do
    for k in 0..(n/a) do
      sum = (a * k) + (b * j) + (c * i)
      if sum == n
        count += 1
      end
    end
  end
end

puts count