#pragma GCC target("avx2")
#pragma GCC optimize("O3,unroll-loops")
#include <stdio.h>
#include <stdlib.h>

const long long sup = 1LL << 60;

void chmin(long long* a, long long b)
{
	if (*a > b) *a = b;
}

long long naive(int N, int X[], int A[])
{
	if (N == 1) {
		if (A[1] == 1) return 0;
		else return -1;
	}

	int i, D[201], A_max = 0;
	for (i = 2; i <= N; i++) D[i] = X[i] - X[i-1];
	for (i = 1; i <= N; i++) if (A_max < A[i]) A_max = A[i];
	A_max *= 2;
	
	int j, jj, k, kk, kkk, cur, prev, L, R;
	long long dp[2][3][10001], tmp;
	for (i = 0; i <= 1; i++) for (j = 0; j <= 2; j++) for (k = 0; k <= A_max; k++) dp[i][j][k] = sup;
	dp[0][0][A[1]*2] = 0;
	dp[0][1][A[1]*2-1] = 0;
	dp[0][2][A[1]*2-2] = 0;
	for (i = 2, cur = 1, prev = 0; i <= N; i++, cur ^= 1, prev ^= 1) {
		for (j = 0; j <= 2; j++) {
			for (k = 0; k <= A_max; k++) {
				if (dp[prev][j][k] == sup) continue;
				tmp = dp[prev][j][k] + (long long)k * D[i];
				dp[prev][j][k] = sup;
				if (k == 0) continue;
				for (jj = 0; jj <= 2 - j; jj++) {
					kk = A[i] * 2 - jj;
					kkk = 0;
					R = k + kk - kkk;
					if (R > A_max) R = A_max;
					kkk = A[i] * 2 - jj;
					if (kkk > k) kkk = k;
					kk = A[i] * 2 - jj - kkk;
					L = k + kk - kkk;
					if (L < 0) L = abs(L) % 2;
					for (kk = L; kk <= R; kk += 2) chmin(&(dp[cur][j+jj][kk]), tmp);
				}
			}
		}
	}
	if (dp[prev][2][0] == sup) return -1;
	else return dp[prev][2][0];
}

int main()
{
	int i, N, X[201], A[201], A_max = 0;
	scanf("%d", &N);
	for (i = 1; i <= N; i++) scanf("%d", &(X[i]));
	for (i = 1; i <= N; i++) scanf("%d", &(A[i]));
	printf("%lld\n", naive(N, X, A));
	fflush(stdout);
	return 0;
}