N = int(input())
A, B = map(int, input().split())
P = list(map(int, input().split()))

for i, p in enumerate(P):
    if p == 1:
        A -= 1
    elif p == 2:
        B -= 1
    else:
        A -= 1
        B -= 1
    if min(A, B) < 0:
        print(i+1)
        break
else:
    print(-1)