from atcoder.dsu import DSU

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

uf = DSU(N)

for _ in range(M):
    u, v = map(int, input().split())
    u -= 1; v -= 1
    if C_list[u] == C_list[v]:
        uf.merge(u, v)

print(len(uf.groups()) - len(set(C_list)))