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
 -  each internal node (a node with at least one son) has at least two sons; -  node *i* has *c*<sub class="lower-index">*i*</sub> 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.
The first line of the input contains integer *n* (1 ≤ *n* ≤ 24). Next line contains *n* positive integers: the *i*-th number represents *c*<sub class="lower-index">*i*</sub> (1 ≤ *c*<sub class="lower-index">*i*</sub> ≤ *n*).
def can_be_a_tree(A, n):
    for i in A:
        if i == 2:
            return False
    return sum(A) == 2 * n - 1


n = int(input())
A = map(int, input().split())
if can_be_a_tree(A, n):
    print("YES")
else:
    print("NO")