Iahub and Iahubina went to a picnic in a forest full of trees. Less than 5 minutes passed before Iahub remembered of trees from programming. Moreover, he invented a new problem and Iahubina has to solve it, otherwise Iahub won't give her the food.
Iahub asks Iahubina: can you build a rooted tree, such that
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each internal node (a node with at least one son) has at least two sons;
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node i has ci nodes in its subtree?
Iahubina has to guess the tree. Being a smart girl, she realized that it's possible no tree can follow Iahub's restrictions. In this way, Iahub will eat all the food. You need to help Iahubina: determine if there's at least one tree following Iahub's restrictions.
The required tree must contain n nodes.
Output
Output on the first line "
YES" (without quotes) if there exist at least one tree following Iahub's restrictions, otherwise output "
NO" (without quotes).