Delete some Minutes of 1-Minute Data (easy data manipulation)

I have 1-Minute OHLC Data, like this:

20170131  14:08   11690.5   11692.0  11689.5  11690.

20170131  14:09   11690.5   11692.0  11689.5  11690.

20170131  14:10   11690.5   11692.0  11689.5  11690.

I get it from MT4->menue->Tool->History Center->Export

Your job is to delete all Minutes which are "ALONE".

It means if there is no minute before this AND no minute after, than delete this minute. Example: 8:05 is ALONE, because 8:04 and 8:06 is missing:

8:00

8:01

8:02

8:05

8:10

8:11

8:12

Job is really ease, but urgend! Please don't apply, if you cant do it in max 2 days, better today. The file contains data from 2012 to now in 1Minute = 33MB.