inc++

you are given a tree with n vertices.Each vartex i has a value ai associated with it.

find the distinctive roots in the tree.

input

the first line of the input contains a single integer n.the number of vertices in the tree.

the next line contains n - seperated integers.

the following n-1 lines each contain 2 seperated integer u and v.

output

print a single integer-the number of distinctive roots in the tree.

input

5

2 5 1 1 4

12

13

14

25

output

3