N = int(input())
apple, banana = map(int, input().split())
orders = list(map(int, input().split))

for i in range(len(orders)):
	if apple == 0 or banana == 0:
		print(i+1)
		break
	else:
		if order == 1:
			apple -= 1
		elif order == 2:
			banana -= 1
		elif order == 3:
			apple -= 1
			banana -= 1
			
print(-1)