amount = 0
sum = 0
for i in range(7):
    list =input().split()
    num1 =int(list[0])
    num2 = int(list[1])
    amount = num1 + num2
    if amount>8:
        print(i+1)
        break
    else:
        sum +=1
if sum ==7:
    print('0')