n = int(input())
apple,banana = map(int,input().split())
line = list(map(int,input().split()))

for key,i in enumerate(line,start=1):
    if i == 1:
        apple -= 1
    elif i == 2:
        banana -= 1
    elif i == 3:
        apple -= 1
        banana -= 1

    if apple == -1 or banana == -1:
        break

if key == n:
    print(-1)
else:
    print(key)