With accent marks:
Слеза́ми го́рю не помо́жешь.
You can't help grief with tears.
This Russian proverb reminds us that belated lamentation and tears often can not change anything in the situation. Better to wipe away your tears and move on, trying not to repeat past mistakes and make the best of what's given to us.
Similar proverbs are found in many other languages.
Other Russian proverbs
Don't bring your set of rules in a foreign monastery
Get your sleigh ready in summer and your (horse-drawn) cart in winter.
You are greeted by your clothes but bid farewell by your mind.
The best is the enemy of the good.
You can't hide an awl in a bag.
You see your friends in the times of trouble.
Laws are not written for fools.
If you like sledding, you should like to carry the sled.