// yukicoder: No.9 モンスターのレベル上げ
// bal4u 2019.8.18

#include <stdio.h>
#include <string.h>

//// 入出力関係
#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif

int in() { // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

//// 優先度付き（最小）キュー

#define MAX 10000
typedef struct { int a, n; } QUE;
QUE que[MAX]; int qsize;
QUE qcp[MAX]; int qsz;

#define PARENT(i) ((i)>>1)
#define LEFT(i)   ((i)<<1)
#define RIGHT(i)  (((i)<<1)+1)

void min_heapify(int i) {
	int l, r, mi;

	l = LEFT(i), r = RIGHT(i);
	if (l < qsize && (que[l].a < que[i].a ||
		que[l].a == que[i].a && que[l].n < que[i].n)) mi = l; else mi = i;
	if (r < qsize && (que[r].a < que[mi].a ||
		que[r].a == que[mi].a && que[r].n < que[mi].n)) mi = r;
	if (mi != i) {
		QUE qt = que[i]; que[i] = que[mi]; que[mi] = qt;
		min_heapify(mi);
	}
}

void deq() {
	que[0] = que[--qsize];
	min_heapify(0);
}

void enq(int a, int n) {
	int i, mi;

	i = qsize++;
	que[i].a = a, que[i].n = n;
	while (i > 0 && (que[i].a < que[mi = PARENT(i)].a ||
		que[i].a == que[mi].a && que[i].n < que[i].n)) {
		QUE qt = que[i]; que[i] = que[mi]; que[mi] = qt;
		i = mi;
	}
}

//// 本問題関連
int N;
int a[1503], b[1503];

int main()
{
	int i, j, k, t, ans;

	N = in();
	for (i = 0; i < N; i++) a[i] = in();
	for (i = 0; i < N; i++) b[i] = in();
	if (N == 1) { puts("1"); return 0; }
	
	ans = N;
	qsize = 0;
	for (i = 0; i < N; i++) enq(a[i], 0);
	memcpy(qcp, que, sizeof(que)), qsz = qsize;

	for (i = 0; i < N; i++) {
		if (i) qsize = qsz, memcpy(que, qcp, sizeof(que));
		t = 0, k = i; for (j = 0; j < N; j++) {
			int x = que[0].a, y = que[0].n+1; deq();
			enq(x + (b[k]>>1), y);
			if (y > t) t = y;
			if (++k == N) k = 0;
		}
		if (t < ans) { ans = t; if (ans == 1) break; }
	}
	printf("%d\n", ans);
	return 0;
}