class UnionFind:
    def __init__(self, n):
        self.n = n
        self.parent_size = [-1] * n
    def leader(self, a):
        if self.parent_size[a] < 0: return a
        self.parent_size[a] = self.leader(self.parent_size[a])
        return self.parent_size[a]
    def merge(self, a, b):
        x, y = self.leader(a), self.leader(b)
        if x == y: return
        if abs(self.parent_size[x]) < abs(self.parent_size[y]): x, y = y, x
        self.parent_size[x] += self.parent_size[y]
        self.parent_size[y] = x
        return
    def same(self, a, b):
        return self.leader(a) == self.leader(b)
    def size(self, a):
        return abs(self.parent_size[self.leader(a)])
    def groups(self):
        result=[[] for _ in range(self.n)]
        for i in range(self.n):
            result[self.leader(i)].append(i)
        return [r for r in result if r != []]

N,M=map(int,input().split())
C=list(map(int,input().split()))
G=[[] for _ in range(N)]
for _ in range(M):
    u,v=map(int,input().split())
    u-=1;v-=1
    G[u].append(v)
    G[v].append(u)

uf=UnionFind(N)
vis=[0 for _ in range(N)]
from collections import deque,defaultdict
Q=deque()
Q.append(0)
while Q:
    cur=Q.popleft()
    vis[cur]=1
    for nxt in G[cur]:
        if C[cur]==C[nxt]:uf.merge(cur,nxt)
        if vis[nxt]==0:Q.append(nxt)
D=defaultdict(set)
for i in range(N):
    L=uf.leader(i)
    D[C[L]].add(L)
ans=0
for k,v in D.items():
    ans+=len(v)-1
print(ans)