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
Do not look at a given horse's teeth.
An old friend is better than two new ones.
Water does not flow under a lying stone.
A well-fed man does not understand a starving one.
Don’t wave your fists after the fight.
Some to the forest, some for firewood.
Poor people are inventive.
There is no smoke without fire.