#codefestival2017qualbb. [code_festival_2017_qualb_b]Problem Set
[code_festival_2017_qualb_b]Problem Set
Problem Statement
Rng is preparing a problem set for a qualification round of CODEFESTIVAL.
He has candidates of problems. The difficulty of the -th candidate is .
There must be problems in the problem set, and the difficulty of the -th problem must be . Here, one candidate of a problem cannot be used as multiple problems.
Determine whether Rng can complete the problem set without creating new candidates of problems.
Constraints
- All numbers in the input are integers.
Partial Score
- points will be awarded for passing the test set satisfying and .
Input
Input is given from Standard Input in the following format:
Output
Print YES
if Rng can complete the problem set without creating new candidates of problems; print NO
if he cannot.
Sample Input 1
Sample Output 1
Sample Input 2
Sample Output 2
Not enough s.