Thanks_up的爱情线

Thanks_up有一条长为n的爱情线，但是ACM不需要爱情，所以他决定把它剪掉，但是Thanks_up有强迫症，

Thanks_up设置了两个规定，1、必须将爱情线剪成长度a，b，c长度的，2、剪完后线必须最多

Thanks_up剪完爱情线后，痛哭流涕不想算，所以他请你们算一下，剪完后爱情线的数量是多少

Thanks_up说了如果你们不能在1s内回答出来，他也把你们的爱情线剪掉

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

第一行包含四个空格分隔的整数n，a，b和c（1≤n，a，b，c≤4000） - 相应地，Thanks_up爱情线的长度和剪后爱情线碎片的可接受长度。 数字a，b和c可以重合。

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

打印一个数字 - 爱情线可能的最大条数。 保证至少存在一个正确的爱情线切割。

5 5 3 2

2

7 5 5 2

2

 Note

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.