# assertion
N, M = map(int, input().split())
assert 1 <= N <= 200000
assert 1 <= M <= 200000

def is_tree(E):
    NNNNN = len(E) + 1
    P = [-1 for i in range(NNNNN)]
    def par(a):
        L = []
        while P[a] >= 0:
            L.append(a)
            a = P[a]
        for l in L:
            P[l] = a
        return a
    def unite(a, b):
        if par(a) != par(b):
            if P[par(b)] >= P[par(a)]:
                if P[par(b)] == P[par(a)]: P[par(a)] -= 1
                P[par(b)] = par(a)
            else:
                P[par(a)] = par(b)
    for a, b in E:
        if not 0 <= a < N: return False
        if not 0 <= b < N: return False
        if par(a) == par(b):
            return False
        unite(a, b)
    return True

A = [int(a) - 1 for a in input().split()]
assert len(A) == M
for a in A:
    assert 0 <= a < N
    
E = [[int(a) - 1 for a in input().split()] for _ in range(N - 1)]
assert is_tree(E)
print(-1, -1)