from collections import defaultdict

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

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

    def unite(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):
        group_members = defaultdict(list)
        for member in range(self.n):
            group_members[self.find(member)].append(member)
        return group_members

    def __str__(self):
        return '\n'.join(f'{r}: {m}' for r, m in self.all_group_members().items())

N, M = map(int, input().split())

C = list(map(int, input().split()))
u = []
v = []

for i in range(M):
    ui, vi = map(int, input().split())
    ui -= 1
    vi -= 1
    u.append(ui)
    v.append(vi)


Ccount = defaultdict(int)
ColorV = [[] for _ in range(N)]
for i in range(N):
    C[i] -= 1
    Ccount[C[i]] += 1
    ColorV[C[i]].append(i)

ColorUFdict: "dict[int, UnionFind]" = {}

v2i = defaultdict(int)
# i: color
for i in range(N):
    if Ccount[i] == 0:
        continue
    uf = UnionFind(Ccount[i])
    ColorUFdict[i] = uf
    for j in range(len(ColorV[i])):
        v2i[ColorV[i][j]] = j

for i in range(M):
    if C[u[i]] == C[v[i]]:
        ColorUFdict[C[u[i]]].unite(v2i[u[i]], v2i[v[i]])

ans = 0

for i in range(N):
    if Ccount[i] == 0:
        continue
    fr = v2i[ColorV[i][0]]
    uf = ColorUFdict[i]
    for x in ColorV[i]:
        to = v2i[x]
        if not uf.same(fr, to):
            ans += 1
            uf.unite(fr, to)

print(ans)