def max_points(K, N, M, pairs):
    can_do = [set() for i in range(K + 1)]
    for a, b in pairs:
        can_do[a].add(b)

    current_points = [0] * (N + 2)
    if T[N - 1] <= K:
        current_points[N - 1] = 1
    if T[N - 2] <= K:
        current_points[N - 2] = 1
        if T[N - 1] in can_do[T[N - 2]]:
            current_points[N - 2] = 2
    for i in range(N - 3, -1, -1):
        if T[i] > K:
            continue
        if T[i + 1] in can_do[T[i]]:
            current_points[i] = 1 + current_points[i + 1]
        if T[i + 2] in can_do[T[i]]:
            current_points[i] = max(current_points[i], 1 + current_points[i + 2])

    return max(current_points[0], current_points[1])


N, K = map(int, input().split())
T = list(map(int, input().split()))
M = int(input())
pairs = [tuple(map(int, input().split())) for _ in range(M)]

print(max_points(K, N, M, pairs))