Buggy python submission (verdict: Time Limit Exceeded):
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 {r: self.members(r) for r in self.roots()}

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

n, m = map(int, input().split())
p = list(map(int, input().split()))
union_find = UnionFind(n)
for _ in range(m):
    x, y = map(int, input().split())
    x -= 1
    y -= 1
    union_find.union(x, y)
res = 0
for root in union_find.roots():
    idx_set = set(union_find.members(root))
    ps_set = set([p[i]-1 for i in union_find.members(root)])
    res += len(idx_set-ps_set)
print(n-res)







Fixed submission:
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 {r: self.members(r) for r in self.roots()}

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

n, m = map(int, input().split())
p = list(map(int, input().split()))
union_find = UnionFind(n)
for _ in range(m):
    x, y = map(int, input().split())
    x -= 1
    y -= 1
    union_find.union(x, y)
res = 0
groups = {}
for i in range(n):
    x = union_find.find(i)
    if x not in groups:
        groups[x] = []
    groups[x].append(i)

for k, v in groups.items():
    idx_set = set(v)
    ps_set = set([p[i]-1 for i in v])
    res += len(idx_set-ps_set)
print(n-res)

Buggy python submission (verdict: Time Limit Exceeded):
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 {r: self.members(r) for r in self.roots()}

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

n, m = map(int, input().split())
p = list(map(int, input().split()))
union_find = UnionFind(n)
for _ in range(m):
    x, y = map(int, input().split())
    x -= 1
    y -= 1
    union_find.union(x, y)
res = 0
for root in union_find.roots():
    include_map = {i: 1 for i in union_find.members(root)}
    for i in union_find.members(root):
        ps = p[i]
        ps -= 1
        if ps in include_map:
            include_map[ps] = 0
    res += sum(include_map.values())
print(n-res)







Fixed submission:
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 {r: self.members(r) for r in self.roots()}

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

n, m = map(int, input().split())
p = list(map(int, input().split()))
union_find = UnionFind(n)
for _ in range(m):
    x, y = map(int, input().split())
    x -= 1
    y -= 1
    union_find.union(x, y)
res = 0
groups = {}
for i in range(n):
    x = union_find.find(i)
    if x not in groups:
        groups[x] = []
    groups[x].append(i)

for k, v in groups.items():
    idx_set = set(v)
    ps_set = set([p[i]-1 for i in v])
    res += len(idx_set-ps_set)
print(n-res)

Buggy python submission (verdict: Time Limit Exceeded):
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 {r: self.members(r) for r in self.roots()}

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

n, m = map(int, input().split())
p = list(map(int, input().split()))
union_find = UnionFind(n)
for _ in range(m):
    x, y = map(int, input().split())
    x -= 1
    y -= 1
    union_find.union(x, y)
res = 0
for root in union_find.roots():
    include_map = {i: 1 for i in union_find.members(root)}
    for i in union_find.members(root):
        ps = p[i]
        ps -= 1
        if ps in include_map:
            include_map[ps] = 0
    res += sum(include_map.values())
print(n-res)



Fixed submission:
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 {r: self.members(r) for r in self.roots()}

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

n, m = map(int, input().split())
p = list(map(int, input().split()))
union_find = UnionFind(n)
for _ in range(m):
    x, y = map(int, input().split())
    x -= 1
    y -= 1
    union_find.union(x, y)
res = 0
groups = {}
for i in range(n):
    x = union_find.find(i)
    if x not in groups:
        groups[x] = []
    groups[x].append(i)

for k, v in groups.items():
    idx_set = set(v)
    ps_set = set([p[i]-1 for i in v])
    res += len(idx_set-ps_set)
print(n-res)