Problems
Cut ribbon
Cut ribbon
Huseyn has a ribbon, its length is n. He wants to cut the ribbon in a way that fulfils the following two conditions:
After the cutting each ribbon piece should have length a, b or c.
After the cutting the number of ribbon pieces should be maximum.
Help Huseyn and find the number of ribbon pieces after the required cutting.
Input data
The first line contains four space-separated integers n, a, b and c~(1 \le n, a, b, c \le 4000) — the length of the original ribbon and the acceptable lengths of the ribbon pieces after the cutting, correspondingly. The numbers a, b and c can coincide.
Output data
Print a single number — the maximum possible number of ribbon pieces. It is guaranteed that at least one correct ribbon cutting exists.
Examples
Input example #1
22 5 2 3
Output example #1
11