while True:
    try:
        #使用map函数简化for循环
        n, x = map(int, input().split())
        a = list(map(int, input().split()))
        b = list(map(int, input().split()))
        total = 0
        for i in range(n):
            total += min(a[i], b[i])
        print(min(total, x))

    except Exception as e:
        break