- Time limit: 1.00 s
- Memory limit: 512 MB
Uolevi is constructing a fence around his garden to prevent rabbits from eating all the tulips. He needs a total of of fence that is at least high. He has planks numbered . The i-th plank is wide and high. All of the planks are shorter than . Uolevi has nails and a hammer but he doesn't own a saw. Help him figure out whether he can make the fence without a saw. For aesthetic reasons, Uolevi is only going to place planks vertically.
Input
The first line contain two integers and . The second line contains integers
Output
Print "Yes" if it is possible to make the fence and "No" otherwise.
Constraints
Example 1
Input:
1 8 3 5
Output:
Yes
Example 2
Input:
5 6 4 2 5 1 4 2 5 1 5 3
Output:
Yes
Example 3
Input:
5 5 1 4 3 4 2 2 2 2 2 1
Output:
No