Question: I connected to my android device (stock android, 10) using ADB on ubuntu, now when I go to /data/ and do ls, it says permission denied.

Why? How to solve this problem?

Answer: 
There can be multiple ways you can write this code. I think you can use two *for* loops here to make it easier for you. I'm using comments so for you being a newbie to understand better. You can choose from these two whichever you find easier to understand:

```
list_of_squares = []               #list to store the squares

for i in range(1, 11):             #since we know 10's square is 100 and we only need numbers less than that
    square = i ** 2
    list_of_squares.append(square) #'append' keeps adding each number's square to this list

for i in range(1, 100):
    if i not in list_of_squares:   #'not in' selects only those numbers that are not in the squares' list
        print(i)

```

Or

```
list_of_squares = []

for i in range(1, 100):
    square = i ** 2
    list_of_squares.append(square)
    if square >= 100:              #since we only need numbers less than 100
        break                      #'break' breaks the loop when square reaches a value greater than or equal to 100

for i in range(1, 100):
    if i not in list_of_squares:
        print(i)

```
You can store the nums that is square of integers into a array.

```
squares =[]
for i in range(1,100):
    squares.append(i**2)

j = 0
for k in range(1,100):
    if k==squares[j]:
        j=j+1
    elif k>squares[j]:
        print(k)
        j=j+1
    else:
        print(k)

```