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
    else:
        A -= 1
        B -= 1

    if A < 0 or B < 0:
        print(i+1)
        exit()
    
print(-1)