import math

def distance(s, g):
    return math.sqrt(pow(s[0] - g[0], 2) + pow(s[1] - g[1], 2))

h, w = map(int, input().split())
p = [input() for i in range(h)] # p[行][列]
_p = [(i, j) for i in range(h) for j in range(w) if p[i][j] == "1"]
length = []

for i in range(h):
    sum = 0
    for e in _p:
        sum += distance((i, -1), e)
    length.append(sum)


for i in range(w):
    sum = 0
    for e in _p:
        sum += distance((-1, i), e)
    length.append(sum)

for i in range(w):
    sum = 0
    for e in _p:
        sum += distance((h, i), e)
    length.append(sum)

for i in range(h):
    sum = 0
    for e in _p:
        sum += distance((i, w), e)
    length.append(sum)

length.sort()
print(length[0])