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 Fortran (gfortran v4.8.4) (judge verdict: Time Limit Exceeded)

implicit none
integer(8) :: i, j, k, n, r, g, b, ans
read(5,*) r, g, b, n
ans = 0
do i = 0, n/r + 1
    do j = 0, n/g + 1
        do k = 0, n/b + 1
            if(r*i+g*j+b*k==n) then
            ans = ans + 1
            endif
        enddo
    enddo
enddo
!write(6, *) r, g, b, n
write(6,"(i0)") ans
end