import math
h, w = map(int, input().split())
p = [list(map(int, list(input().strip()))) for i in range(h)]
c = []
for i in range(h):
    for j in range(w):
        if p[i][j] == 1:
            c.append((i+1,j+1))
cost = []
for i in range(1,h+1):
    cost.append(sum([math.sqrt((x-i)**2 + y**2) for x, y in c]))
    cost.append(sum([math.sqrt((x-i)**2 + (y-(w+1))**2) for x, y in c]))

for i in range(1,w+1):
    cost.append(sum([math.sqrt(x**2 + (y-i)**2) for x, y in c]))
    cost.append(sum([math.sqrt((x-(h+1))**2 + (y-i)**2) for x, y in c]))

print(min(cost))