n = int(input())
a,b = map(int,input().split())
l = list(map(int,input().split()))
i = 0


while  i < n and a > -1 and b > -1:
  
    
    if l[i] == 1:
        a -= 1
    elif l[i] == 2:
        b -= 1
    else:
        a -= 1
        b -= 1
    i += 1
  

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