## https://yukicoder.me/problems/no/707

import math

def main():
    H, W = map(int, input().split())
    P = []
    for _ in range(H):
        P.append(input())

    H += 2
    W += 2
    p_list = [[-1] * W for _ in range(H)]
    for h in range(1, H - 1):
        for w in range(1, W - 1):
            p_list[h][w] = int(P[h - 1][w - 1])
    
    boundaries = []
    for h in range(H):
        for w in range(W):
            if h in (0, H - 1) or w in (0, W - 1):
                boundaries.append((h, w))
    
    answer = float("inf")
    for h0, w0 in boundaries:
        ans = 0
        for h in range(1, H - 1):
            for w in range(1, W - 1):
                if p_list[h][w] == 1:
                    d = (h - h0) **2 + (w - w0) ** 2
                    d = math.sqrt(d)
                    ans += d
        answer = min(answer, ans)
    print(answer)










if __name__ == "__main__":
    main()