from sys import stdin
from decimal import *

def besokNode(nabomatrise, node, nodeIkkeBesokt, kanter, noder, n):
	
	nodeIkkeBesokt[node] = False
	noder -= 1
	
	for i in xrange(0,n):
		if nabomatrise[i][node]:
			kanter -=1
		if nabomatrise[node][i]:
			if nodeIkkeBesokt[i]:
				kanter, noder = besokNode(nabomatrise, i, nodeIkkeBesokt, kanter, noder, n)
	
	return (kanter, noder)
	
def main():

	n = int(stdin.readline())
	nabomatrise = [None] * n # rader
	tK = 0

	for i in xrange(0, n):
		nabomatrise[i] = [False] * n # kolonner
		linje = stdin.readline()
		for j in xrange(0, n):
			if linje[j] == '1':
				tK +=1
				nabomatrise[i][j] = True

	for startnoden in stdin:
		
		noder = n
		kanter = tK
		
		nodeIkkeBesokt = []
		nodeIkkeBesokt = [True] * n
		
		startnode = int(startnoden)
		
		kanter, noder = besokNode(nabomatrise, startnode, nodeIkkeBesokt, kanter, noder, n)
		
		if noder == 0:
			print "0.000"
		else:
			print "%.3f" % ((float(kanter) / float(noder**2)) + 1E-12)

main()