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 PyPy3 (2.4.0) (judge verdict: Accepted)

R, G, B, N = map(int, input().split())

ans = 0
rsum = 0
for r in range(0, N+1):
    if N < rsum:
        break
    rgsum = rsum
    for g in range(0, N+1):
        if N < rgsum:
            break
        left = N - rgsum
        if left % B == 0:
            ans += 1
        rgsum += G
    rsum += R

print(ans)