#include <stdio.h>
#include <string.h>
#define N 500000
#define N_ (1 << 19) /* N_ = pow2(ceil(log2(N))) */
#define INF 0x3f3f3f3f3f3f3f3fLL
long long min(long long a, long long b) { return a < b ? a : b; }
unsigned int X = 12345;
int rand_() {
return (X *= 3) >> 1;
}
int *vv;
void sort(int *ii, int l, int r) {
while (l < r) {
int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;
while (j < k)
if (vv[ii[j]] == vv[i_])
j++;
else if (vv[ii[j]] < vv[i_]) {
tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
i++, j++;
} else {
k--;
tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
}
sort(ii, l, i);
l = k;
}
}
long long ss[N_ * 2], dd[N_ * 2]; int n_;
void pul(int i) {
int l = i << 1, r = l | 1;
ss[i] = ss[l] + ss[r];
dd[i] = min(dd[l], dd[r] == INF ? INF : dd[r] - ss[l]);
}
void build(int n) {
int i;
n_ = 1;
while (n_ < n)
n_ <<= 1;
memset(dd + n_, 0x3f, n_ * sizeof *dd);
for (i = n_ - 1; i > 0; i--)
pul(i);
}
void update(int i, int x, long long y) {
i += n_;
ss[i] = x, dd[i] = y == INF ? INF : y - x;
while (i > 1)
pul(i >>= 1);
}
int main() {
static int xx[N], yy[N], ii[N], idx[N];
int n, h, i, k;
scanf("%d", &n);
for (i = 0; i < n; i++)
scanf("%d", &xx[i]);
for (i = 0; i < n; i++)
scanf("%d", &yy[i]), yy[i] += xx[i];
for (i = 0; i < n; i++)
ii[i] = i;
vv = yy, sort(ii, 0, n);
for (i = 0; i < n; i++)
idx[ii[i]] = i;
vv = xx, sort(ii, 0, n);
build(n);
k = 0;
for (h = 0; h < n; h++) {
i = ii[h];
update(idx[i], xx[i], yy[i]);
if (dd[1] >= 0)
k++;
else
update(idx[i], 0, INF);
}
printf("%d\n", k);
return 0;
}
