n,m = map(int, input().split())
l = []
for i in range(n):
    a = input()
    a.split()
    l.append(a)
def f(x,y):
    global l ,n,m
    ans = -3
    if l[x][y] == "#":
        return 0
    else :
        for i in range(x,n):
            if l[i][y] == ".":
                ans += 1
            else :
                break
        for i in range(x+1):
            if l[x-i][y] == ".":
                ans += 1
            else :
                break
        for i in range(y,m):
            if l[x][i] == ".":
                ans += 1
            else :
                break
        for i in range(y+1):
            if l[x][y-i] == ".":
                ans += 1
            else:
                break
        return ans
k = 1
for i in range(n):
    for j in range(m):
        k = max(k,f(i,j))
        if k == n + m - 1:
            break
print(k)
