More than two similar lines in a row fits me

I've got the .txt file like this within:

....

Crista

7:3

2:0

Wiki

4:1

6:2

3:2

6:8

Pope

5:2

0:1

....

Code to find all lines with digits and append it to list:

pp=open('mine.txt')
ll=[]

for line in pp:
    line = line.rstrip()
    if re.findall('^\d{1}:\d{1}', line):
        digits=line
        ll.append(digits)

My output:

ll=['7:3', '2:0', '4:1', '6:2', '3:2', '6:8', '5:2', '0:1']

If there's more than two lines with digits in a row I don't need them in the list

So my desired output is:

ll=['7:3', '2:0', '4:1', '6:2', '5:2', '0:1']

How can I get it?