CF189A Cut Ribbon

Polycarpus 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 Polycarpus and find the number of ribbon pieces after the required cutting.

The first line contains four space-separated integers $ n $ , $ a $ , $ b $ and $ c $ $ (1

Print a single number — the maximum possible number of ribbon pieces. It is guaranteed that at least one correct ribbon cutting exists.

In the first example Polycarpus can cut the ribbon in such way: the first piece has length 2, the second piece has length 3. In the second example Polycarpus can cut the ribbon in such way: the first piece has length 5, the second piece has length 2.