import sequtils,strutils,math
var
    A = newSeq[string](0)
    H,W : int
    px,py : int
    ans : float64
(H, W) = stdin.readline.split.map(parseInt)

A.add("0")
for line in stdin.lines:
    A.add("0" & line & "0")

proc cul(a, b : int) : float64 =
    var
        r : int
        R : float64
    for x in 1..W:
        for y in 1..H:
            if A[y][x] == '1':
                r = (x - a) * (x - a) + (y - b) * (y - b)
                R += sqrt(r.float64)
    return R

ans = INF
for i in 1..H:
    ans = min(ans, cul(0, i))
    ans = min(ans, cul(W + 1, i))
for i in 1..W:
    ans = min(ans, cul(i, 0))
    ans = min(ans, cul(i, H + 1))
    
echo ans