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
A bad example is contagious.
You see your friends in the times of trouble.
What you will sow, that you will reap.
Measure seven times, cut one.
The demon is not as scary as he is depicted.
Without labor, you can not even catch a fish in the pond.
Where it is thin, it breaks.
There are no friends for taste and color.