How to understand 「数えりゃ」in a song lyric


For a project for school (compulsory song research), I have chosen
[緑黄色社会の『sabotage』 (time 1:48)](https://www.youtube.com/watch?v=FWQzurioulQ); a
requirement is that I understand what is being said, so I proceeded with the
translation process. I was fine until this line showed up, near the middle of
the song lyrics:

**数(かぞ)えりゃ1,2,3,4, and 5,6,7...**

I am confused on the first part concerning 「数えりゃ」; I see how it is partly 数える,
to count, but then there is りゃ, and I am unsure if this has any meaning; I
know this is not an inflection (what has えりゃ as an attachment?), but I do not
want to disregard what nuance it could add. What exactly does 「数えりゃ」 mean, or
does it not have any meaning? If beneficial, the previous line was talking on
how the partner in a relationship keeps making mistakes, and I assume the line
in question is a continuation of the number of mistakes.

