# -*- coding: utf-8 -*-
import numpy as np

X = []
Y = []

H, W = map(int, input().split())

for h in range(1, H+1):
    for w, v in enumerate(map(int, input()), start=1):
        if v==0:
            continue
        X.append(w)
        Y.append(h)

gX = np.array(X, dtype=np.float64).reshape(1, -1)
gY = np.array(Y, dtype=np.float64).reshape(1, -1)

rX = np.array([0]*H + [W+1]*H + list(range(1, W+1)) + list(range(1, W+1)), dtype=np.float64).reshape(1, -1)
rY = np.array(list(range(1, H+1)) + list(range(1, H+1)) + [0]*W + [H+1]*W, dtype=np.float64).reshape(1, -1)

print(np.min(np.sum(np.sqrt(np.power(gX-rX.T, 2) + np.power(gY-rY.T, 2)), axis=1)))