There are $N$ people numbered $1$ to $N$.
You are given their schedule for the following $D$ days. The schedule for person $i$ is represented by a string ��Si of length $D$. If the $j$-th character of ��Si is o, person $i$ is free on the $j$-th day; if it is x, they are occupied that day.

From these $D$ days, consider choosing some consecutive days when all the people are free.
How many days can be chosen at most? If no day can be chosen, report $0$.

The input is given from Standard Input in the following format:

N

s1

s2

...

sN

Print the maximum number of days that can be chosen, or 0 if no day can be chosen.

• $1\le N\le 100$

• $1\le D\le 100$

• $N$ and $D$ are integers.

• ��Si is a string of length $D$ consisting of o and x.

first

All the people are free on the second and third days, so we can choose them.
Choosing these two days will maximize the number of days among all possible choices.

second

Note that the chosen days must be consecutive. (All the people are free on the first and third days, so we can choose either of them, but not both.)

input4

1 7
ooooooo

output4

7

input5

5 15

5 15
oxooooooooooooo
oxooxooooooooox
oxoooooooooooox
oxxxooooooxooox
oxooooooooxooox

output5

5