N = int(input())
A, B= map(int, input().split())
P = list(map(int, input().split()))
for i in range(N):
	if P[i] == 1:
		A -= 1
	elif P[i] == 2:
		B -= 1
	elif P[i] == 3:
		A -= 1
		B -= 1
	if A < 0 or B < 0:
		print(i+1)
		exit()
if i == N -1 :
	print(-1)