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

for i in range(N):
    pi = p[i]
    # print(pi)
    match pi:
        case 1:
            apple -= 1
        case 2:
            banana -= 1
        case 3:
            apple -= 1
            banana -= 1
    # print(f"{apple=}")
    # print(f"{banana=}")
            
    if apple<0 or banana<0:
        print(i+1)
        exit()
print(-1)