can you help me to write this pattern [closed]

We want to put all the strings of length n consisting of the letters 0 and 1 in a row in such a way that if we write the two adjacent strings in a column, they will differ from each other in only one letter.

1<=n<=15

ex)please enter number:2

00

01

11

10

ex) please enter number:3

000

001

011

010

110

111

101

100