n,k = map(int,input().split()) prince = list(map(int,input().split()))
flag2 = input() flag = [] for i in flag2: flag.append(int(i)) prince2 = [] for i,j in enumerate(prince): val = j*0.95 if flag[i] else j prince2.append(val) prince2.sort() ans = 0 for i in prince2: k-=i if k>=0: ans+=1 else: break print(ans)