import math

H, W = map(int, input().split())
l = []
for i in range(H):
    ll = ["0"] + list(input()) + ["0"]
    l.append(ll)
l = [["0" for i in range(W + 2)]] + l + [["0" for i in range(W + 2)]]

print(l)
best_ans = 10000000000
for i in range(H + 2):
    for j in range(W + 2):
        if 0 < i < H + 1 and 0 < j < W + 1:
            continue
        if i == j == 0:
            continue
        if i == 0 and j == W + 1:
            continue
        if j == 0 and i == H + 1:
            continue
        if i == H + 1 and j == W + 1:
            continue
        ans = 0
        for cki in range(H + 2):
            for ckj in range(W + 2):
                if l[cki][ckj] == "1":
                    ans += math.sqrt(pow(i - cki,2) + pow(j - ckj,2)) 
        best_ans = min(best_ans,ans)

print(best_ans)