n = int(input())
a, b = map(lambda s_: int(s_), input().split())
p = tuple(map(lambda s_: int(s_), input().split()))

coa = [0, 1, 0, 1]
cob = [0, 0, 1, 1]
for i, pi in enumerate(p, 1):
    a -= coa[pi]
    b -= cob[pi]
    if a < 0 or b < 0:
        print(i)
        break
else:
    print(-1)