def find(x):
    if P[x] == x: return x
    else:
        P[x] = find(P[x]) #経路圧縮
        return P[x]
        # return find(P[x]) #経路圧縮なし

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

def merge(x,y):
    x = find(x)
    y = find(y)
    if x == y: return 0
    if x > y: x,y = y,x
    P[y] = x

N,M = map(int,input().split())
P = [i for i in range(N)]
C = list(map(int,input().split()))
G = [[] for _ in range(N)]
for i,c in enumerate(C):
    c -= 1
    G[c].append(i)

for i in range(M):
    u,v = map(int,input().split())
    u -= 1
    v -= 1
    if C[u] == C[v]:
        merge(u,v)

ans = 0
for i in range(N):
    if G[i]:
        if len(G[i]) == 1:
            continue
        ng = len(G[i])
        for j in range(1,ng):
            if not same(G[i][0],G[i][j]):
                merge(G[i][0],G[i][j])
                ans += 1
print(ans)