If have this text

2
2


1
1
1
1
1
1

If I go to the first '2', press 'shift-v j yto yank both 2s lines, then move to the first 1 and paste withP`

I expected to have

2
2


2
2
1
1
1
1
1
1

But instead I have

2
2


21
21
1
1
1
1

How can I have the expected behavior?