import sys

input = sys.stdin.readline



def main():

    n,m = list(map(int,input().split()))

    p = list(map(int,input().split()))

    xy = [list(map(int,input().split())) for _ in range(m)]



    class UnionFind(object):

        def __init__(self, n=1):

            self.par = [i for i in range(n)]

            self.rank = [0 for _ in range(n)]

            self.size = [1 for _ in range(n)]



        def find(self, x):

            if self.par[x] == x:

                return x

            else:

                self.par[x] = self.find(self.par[x])

                return self.par[x]



        def union(self, x, y):

            x = self.find(x)

            y = self.find(y)

            if x != y:

                if self.rank[x] < self.rank[y]:

                    x, y = y, x

                if self.rank[x] == self.rank[y]:

                    self.rank[x] += 1

                self.par[y] = x

                self.size[x] += self.size[y]



        def all_group_members(self):

            return_list = [list() for i in range(n)]

            for i in range(n):

              return_list[self.find(i)].append(i)

            return return_list



    uf = UnionFind(n)

    ans = 0

    for x,y in xy:

        uf.union(x-1,y-1)

    for v in uf.all_group_members():

        set1 = set()

        for i in v:

            set1.add(p[i]-1)

        ans += len(set(v)&set1)



    print(ans)



if __name__ == '__main__':

    main()

import sys

input = sys.stdin.readline



def main():

    n,m = list(map(int,input().split()))

    p = list(map(int,input().split()))

    xy = [list(map(int,input().split())) for _ in range(m)]



    class UnionFind():

        def __init__(self, n):

            self.n = n

            self.parents = [-1] * n



        def find(self, x):

            if self.parents[x] < 0:

                return x

            else:

                self.parents[x] = self.find(self.parents[x])

                return self.parents[x]



        def union(self, x, y):

            x = self.find(x)

            y = self.find(y)



            if x == y:

                return



            if self.parents[x] > self.parents[y]:

                x, y = y, x



            self.parents[x] += self.parents[y]

            self.parents[y] = x



        def size(self, x):

            return -self.parents[self.find(x)]



        def same(self, x, y):

            return self.find(x) == self.find(y)



        def members(self, x):

            root = self.find(x)

            return [i for i in range(self.n) if self.find(i) == root]



        def roots(self):

            return [i for i, x in enumerate(self.parents) if x < 0]



        def group_count(self):

            return len(self.roots())



        def all_group_members(self):

            return_list = [list() for i in range(n)]

            for i in range(n):

              return_list[self.find(i)].append(i)

            return return_list



        def __str__(self):

            return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())



    uf = UnionFind(n)

    ans = 0

    for x,y in xy:

        uf.union(x-1,y-1)

    for v in uf.all_group_members():

        set1 = set()

        for i in v:

            set1.add(p[i]-1)

        ans += len(set(v)&set1)



    print(ans)



if __name__ == '__main__':

    main()

import sys

input = sys.stdin.readline


def main():
    n, m = list(map(int, input().split()))
    p = list(map(int, input().split()))
    xy = [list(map(int, input().split())) for _ in range(m)]

    class UnionFind(object):
        def __init__(self, n=1):
            self.par = [i for i in range(n)]
            self.rank = [0 for _ in range(n)]
            self.size = [1 for _ in range(n)]

        def find(self, x):
            if self.par[x] == x:
                return x
            else:
                self.par[x] = self.find(self.par[x])
                return self.par[x]

        def union(self, x, y):
            x = self.find(x)
            y = self.find(y)
            if x != y:
                if self.rank[x] < self.rank[y]:
                    x, y = y, x
                if self.rank[x] == self.rank[y]:
                    self.rank[x] += 1
                self.par[y] = x
                self.size[x] += self.size[y]

        def all_group_members(self):
            return_list = [list() for i in range(n)]
            for i in range(n):
                return_list[self.find(i)].append(i)
            return return_list

    uf = UnionFind(n)
    ans = 0
    for x, y in xy:
        uf.union(x - 1, y - 1)
    for v in uf.all_group_members():
        set1 = set()
        for i in v:
            set1.add(p[i] - 1)
        ans += len(set(v) & set1)
    print(ans)


if __name__ == "__main__":
    main()

import sys

input = sys.stdin.readline


def main():
    n, m = list(map(int, input().split()))
    p = list(map(int, input().split()))
    xy = [list(map(int, input().split())) for _ in range(m)]

    class UnionFind:
        def __init__(self, n):
            self.n = n
            self.parents = [-1] * n

        def find(self, x):
            if self.parents[x] < 0:
                return x
            else:
                self.parents[x] = self.find(self.parents[x])
                return self.parents[x]

        def union(self, x, y):
            x = self.find(x)
            y = self.find(y)
            if x == y:
                return
            if self.parents[x] > self.parents[y]:
                x, y = y, x
            self.parents[x] += self.parents[y]
            self.parents[y] = x

        def size(self, x):
            return -self.parents[self.find(x)]

        def same(self, x, y):
            return self.find(x) == self.find(y)

        def members(self, x):
            root = self.find(x)
            return [i for i in range(self.n) if self.find(i) == root]

        def roots(self):
            return [i for i, x in enumerate(self.parents) if x < 0]

        def group_count(self):
            return len(self.roots())

        def all_group_members(self):
            return_list = [list() for i in range(n)]
            for i in range(n):
                return_list[self.find(i)].append(i)
            return return_list

        def __str__(self):
            return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots())

    uf = UnionFind(n)
    ans = 0
    for x, y in xy:
        uf.union(x - 1, y - 1)
    for v in uf.all_group_members():
        set1 = set()
        for i in v:
            set1.add(p[i] - 1)
        ans += len(set(v) & set1)
    print(ans)


if __name__ == "__main__":
    main()

-    class UnionFind(object): -        def __init__(self, n=1): -            self.par = [i for i in range(n)] -            self.rank = [0 for _ in range(n)] -            self.size = [1 for _ in range(n)] +    class UnionFind: +        def __init__(self, n): +            self.n = n +            self.parents = [-1] * n -            if self.par[x] == x: +            if self.parents[x] < 0: -                self.par[x] = self.find(self.par[x]) -                return self.par[x] +                self.parents[x] = self.find(self.parents[x]) +                return self.parents[x] -            if x != y: -                if self.rank[x] < self.rank[y]: -                    x, y = y, x -                if self.rank[x] == self.rank[y]: -                    self.rank[x] += 1 -                self.par[y] = x -                self.size[x] += self.size[y] +            if x == y: +                return +            if self.parents[x] > self.parents[y]: +                x, y = y, x +            self.parents[x] += self.parents[y] +            self.parents[y] = x + +        def size(self, x): +            return -self.parents[self.find(x)] + +        def same(self, x, y): +            return self.find(x) == self.find(y) + +        def members(self, x): +            root = self.find(x) +            return [i for i in range(self.n) if self.find(i) == root] + +        def roots(self): +            return [i for i, x in enumerate(self.parents) if x < 0] + +        def group_count(self): +            return len(self.roots()) + +        def __str__(self): +            return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots())