With accent marks:
Терпи́, каза́к – атама́ном ста́нешь!
Be patient, Cossack - you will become an ataman!
This expression is often used in a joking manner to encourage a person to patiently endure difficulties.
The expression itself is a catch phrase from the Gogol's novel "Taras Bulba". When the Cossack army surrounded the city of Dubno and a long siege began, one young Cossack got bored, and Taras said to him: "Be patient, Cossack - you will become an ataman!" Ataman is a Cossack leader.
Other Russian proverbs
Hurry to much and you will make people laugh.
Don't bring your set of rules in a foreign monastery
Bitter truth is better than sweet lies.
When the job is done, you can go for a walk.
The beauty of a debt is its payment
In a quiet whirlpool, demons live.
The best is the enemy of the good.
The apple never falls far from the tree.