number.... text..... convert..... HEADACHE!

So, my problem is simple but for the life of me I cannot figure it out.

I have a time in F2 12:35
In G2 I want to display the first two digits of the time 12

I tried =left(f2,2) but thats just for text

I need to sort arrivals by hour and then give average length of stay based on arrival by hour...

Any help would be greatly appreciated!

TLS