[Lucas89]

合って is the て form of 合う

And the ん before です is just short for の, which you will hear alot in speech just like the missing い in いる or います

Edit:
Another thing that caught me out the first time i saw it was the same thing but for nouns and -na adjectives.
So you might see for example

学生なんだ or 静かなんだ

Although those are obviously not full sentences, 学生 being a noun and 静か being a -na adjective they have to use なの instead of just の after them, so again the の can be shortened to ん to make なん

if you don't do this it could change the meaning.

学生なんだ - He/She/It/Whatever is a student.
学生のだ - It is student's (The possessive の)

I'm not sure if i have explained very well so maybe someone else will do a better job