The answer is a well known phrase.
3443355
Hint1
The numbers at the bottom are related to the string of letters at the top of the image... but how?
Hint2
Sum of the digits?
Hint3 (A bit more decisive. Hoping someone will crack this.)
I initially planned to write them as (3) (4) (4) (3) (3) (5) (5), but thought to myself that would be a lot more obvious. Also, in case you thought that the string of letters are initials of countries - they're not.