With accent marks:
За двумя́ за́йцами пого́нишься – ни одного́ не пойма́ешь.
If you are chasing two hares at once, you won’t catch a single one.
This Russian proverb addresses the problems of multitasking: doing several things at the same time will not give you good results.
The expression dates back to primitive times when hunters were stubbornly chasing just one hare until he was completely exhausted. If you chase two hares at once, giving a respite to one or the other, then soon you will be exhausted yourself and the hares will safely flee.
A close English equivalent of this proverb, although with an opposite meaning, is "to kill two birds with one stone".
Other Russian proverbs
Beast runs towards the hunter.
Each sandpiper praises its swamp.
Where it is thin, it breaks.
Silent means consent.
Live for a century, learn for a century, but die being a fool anyway.
Do not look at a given horse's teeth.
Do not dig a hole for another one, you will fall into it yourself.
Being a guest is good, but being at home is better.