Can any one help me solve this

Checkout the editorial of the problem here
Basically N can be written as:
=> 2020*x+2020*y+y=N
=> 2020*(x+y)=N-y
=>x=(N-y)/(2020) -y

So now simply check if x is greater than 0 and RHS is a whole number. If true YES, else NO.



Since x>0

N-2021y > 0

=> y<N/2021

Run a loop of y from 1 to floor(N/2021) and check if any integer solution of x exists.