N = int(input())
*A, = map(int, input().split())
*X, = map(int, input().split())
*Y, = map(int, input().split())


N0 = 2**(N-1).bit_length()
A = A + [10**6] * (N0 - N)
data = [None]*(2*N0+1)

# Li Chao Tree
def f(line, x):
    p, q = line
    return p*x + q

def _add_line(line, a, b, k, l, r):
    if r <= a or b <= l:
        return
    m = (l + r) // 2
    if not (a <= l and r <= b):
        _add_line(line, a, b, 2*k+1, l, m)
        _add_line(line, a, b, 2*k+2, m, r)
        return
    if data[k] is None:
        data[k] = line
        return
    lx = A[l]
    mx = A[m]
    rx = A[r-1]
    left = (f(line, lx) < f(data[k], lx))
    mid = (f(line, mx) < f(data[k], mx))
    right = (f(line, rx) < f(data[k], rx))
    if left and right:
        data[k] = line
        return
    if not left and not right:
        return
    if mid:
        data[k], line = line, data[k]
    if left != mid:
        _add_line(line, 2*k+1, l, m)
    else:
        _add_line(line, 2*k+2, m, r)

def add_line(line, a, b):
    return _add_line(line, a, b, 0, 0, N0)

def query(k, x):
    def gen(k, x):
        k += N0-1
        while k >= 0:
            if data[k]:
                yield f(data[k], x)
            k = (k - 1) // 2
    return min(gen(k, x))

v = 0
j = 0
for i in range(N):
    x = X[i]; a = A[i]; y = Y[i]
    while A[j+1] < x:
        j += 1
    add_line((-1, x+y+v), 0, j)
    add_line((1, -x+y+v), j, N0)
    v = query(i, a)
print(v)