#!/usr/bin/env python3
import math
h, w = map(int, input().split())
p = [ list(map(int, input())) for _ in range(h) ]
pos = []
pos += [ (y, -1) for y in range(h) ]
pos += [ (y,  w) for y in range(h) ]
pos += [ (-1, x) for x in range(w) ]
pos += [ (w,  x) for x in range(w) ]
answer = math.inf
for y0, x0 in pos:
    acc = 0
    for y1 in range(h):
        for x1 in range(w):
            if p[y1][x1]:
                acc += math.hypot(x1 - x0, y1 - y0)
    answer = min(answer, acc)
print(answer)