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 Go (1.6) (judge verdict: Time Limit Exceeded)

package main

import (
  "fmt"
)

func main() {
  var (
    r,g,b,n int
    ans int
    )
  fmt.Scan(&r)
  fmt.Scan(&g)
  fmt.Scan(&b)
  fmt.Scan(&n)

  rm := n/r
  gm := n/g
  bm := n/b

  for ri := 0;ri <= rm; ri ++ {
    for gi:=0;gi <= gm; gi++ {
      for bi:=0;bi<=bm;bi++ {
        if r * ri + g * gi + b * bi == n {
          ans += 1
        }
      }
    }
  }
  fmt.Println(ans)

}