N = int(input())
A,B = map(int,input().split())
P = list(map(int,input().split()))

for i,p in enumerate(P):
    if p==1:
        A -= 1
    elif p==2:
        B -= 1
    else:
        A -= 1
        B -= 1
    if A < 0 or B < 0:
        print(i+1)
        exit()
print(-1)