n = int(input())
A, B = map(int, input().split())
p = list(map(int, input().split()))

cnt = 0
for i in range(n):
    cnt += 1
    if p[i]==1:
        A -= 1
    elif p[i]==2:
        B -= 1
    else:
        A -= 1
        B -= 1
    
    if A==-1 or B==-1:
        print(cnt)
        exit()
print(-1)