def bubble_sort(target):
    ans = []
    for n in range(len(target) - 1, 0, -1):
        for i in range(n):
            if target[i] > target[i + 1]:
                ans.append((i + 1, i + 2))
                target[i], target[i + 1] = target[i + 1], target[i]

    return ans[::-1]


def sim(now, line):
    m = dict()
    for i in range(1, len(now) + 1):
        no = i
        for x, y in line:
            if no == x:
                no = y
            elif no == y:
                no = x
        # now[i - 1]番は棒noに
        m[no] = now[i - 1]
    to = []
    for k, v in sorted(m.items()):
        to.append(v)
    return to


def main():
    n = int(input())
    k = int(input())
    l = []
    for _ in range(k):
        x, y = map(int, input().split())
        l.append((x, y))
    target = list(map(int, input().split()))

    to = sim(list(range(1, n + 1)), l)
    m = dict()
    for i in range(1, len(to) + 1):
        m[to[i - 1]] = i

    t = sorted([(x, i) for i, x in enumerate(target, start=1)])
    t = [m[x] for i, x in t]

    ans = bubble_sort(t)
    print(len(ans))
    for x in ans:
        print(x[0], x[1])

if __name__ == '__main__':
    main()