The week of November 16, 1965, found The Supremes atop the Billboard Hot 100 with ‘I Hear a Symphony,’ one of 12 #1 hits for the legendary girl group.
At #2 that week was Len Barry’s ‘1-2-3,’ a song that ended up embroiled in a copyright claim by those very same Supremes. Motown sued Barry and his co-writers, claiming that ‘1-2-3’ bore a strong resemblance to The Supremes’ ‘Ask Any Girl.‘ After two years in the courts, Motown’s Holland–Dozier–Holland writing team was awarded 15% of the royalties from this song.
I hear the resemblance, though I’d say both songs sound a lot like a half dozen other compositions from the era. There are only so many notes, after all.
This was by far the biggest hit for Barry as a solo act, though he had reached #2 once before with ‘Bristol Stomp’ in 1961 as lead singer of The Dovells.
One, two, three
Oh! That’s how element’ry?
It’s gonna be
Come on, let’s fall in love!
[Chorus]
It’s easy
It’s so easy
Like taking candy
Like taking candy
From a baby
[Verse 2]
A-B-C
A-B-C
Falling in love with you was
Easy for me
Easy for me
And you can do it too
[Chorus]
It’s easy
It’s so easy
Like taking candy
Like taking candy
From a baby
[Bridge]
Baby! There’s nothing hard about love
Basicly, it’s as easy as pie
The hard part
Is living without love
Without your love, baby! I would die
[Refrain]
One, two, three
One, two, three
[Chorus]
It’s easy
It’s so easy
Like taking candy
Like taking candy
From a baby, yeah!
[Verse 3]
One and one are two
One and one are two
I know you love me and, oh! Oh!
How I love you?
How I love you?
Don’t try to fight it
[Chorus]
‘Cuz it’s easy
It’s so easy
Like taking candy
Like taking candy
From a baby, hey!
[Verse 4]
One, two, three
One, two, three
Oh! That’s how element’ry?
It’s gonna be
It’s gonna be
Come on, let’s fall in love!
[Outro]
It’s easy (One, two, three)
Oh! That’s how element’ry?
Meet Me In Montauk 
I certainly hear the similarity, but tend to agree that both songs are styled like many other Motown songs.