h, w = map(int, input().split())
P = [input() for _ in range(h)]

ans = float("inf")
for i in [-1, h]:
    for j in range(w):
        tot = 0
        for ii in range(h):
            for jj in range(w):
                if P[ii][jj] == "1":
                    tot += ((i - ii) ** 2 + (j - jj) ** 2) ** 0.5
        ans = min(ans, tot)
        
for j in [-1, w]:
    for i in range(h):
        tot = 0
        for ii in range(h):
            for jj in range(w):
                if P[ii][jj] == "1":
                    tot += ((i - ii) ** 2 + (j - jj) ** 2) ** 0.5
        ans = min(ans, tot)
print(ans)