H,W=map(int,input().split())
R=[list(map(int,list(input()))) for h in range(H)]
ans=1e20
HW=[]
for h in range(1,H+1):
    HW.append((h,0))
    HW.append((h,W+1))
for w in range(1,W+1):
    HW.append((0,w))
    HW.append((H+1,w))
for h,w in HW:
    d=0
    for x in range(H):
        for y in range(W):
            if R[x][y]:
                d+=((x+1-h)**2+(y+1-w)**2)**.5
    ans=min(ans,d)
print(ans)