import sys
input=lambda: sys.stdin.readline().rstrip()
h,w=map(int,input().split())
P=[input() for _ in range(h)]

def dist(x1,y1,x2,y2):
	return ((x1-x2)**2+(y1-y2)**2)**0.5

def f(x,y):
	ret=0
	for i in range(h):
		for j in range(w):
			if P[i][j]=="1":
				ret+=dist(x,y,i+1,j+1)
	return ret

ans=float("inf")
for i in range(w):
	ans=min(ans,f(i+1,0))
	ans=min(ans,f(i+1,h+1))
for i in range(h):
	ans=min(ans,f(0,i+1))
	ans=min(ans,f(w+1,i+1))
print(ans)