Grid

n = int(input())

table = []
for _ in range(n):
	table.append(list(input().rstrip()))
#print(table)

def areAllOnes(row):
	for j in range(len(row)):
		if row[j] == "0":
			return False
	return True

oneRows = []
neededMoves = 0
for row in range(n):
	if areAllOnes(table[row]):
		oneRows.append(row)
		neededMoves += 1
oneCols = []
for i in range(n):
	allOnes = True
	for j in range(n):
		if table[j][i] == "0":
			allOnes = False
			break
	if allOnes == True:
		oneCols.append(i)
		#print("COL FOUND")
		neededMoves += 1
	
if neededMoves == n*2:
	neededMoves = n
for i in range(n):
	for j in range(n):
		if table[i][j] == "1" and i not in oneRows and j not in oneCols:
			neededMoves = -1
print(neededMoves)

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: TIME LIMIT EXCEEDED

Test 22

Verdict: TIME LIMIT EXCEEDED