#include <bits/stdc++.h>
using namespace std;

using i32 = int;
using i64 = long long;
using i128 = __int128_t;
using f64 = double;
using p2 = pair<i64, i64>;
using p3 = tuple<i64, i64, i64>;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(18);
  _main();
}

void _main() {
  i64 n;
  cin >> n;
  i64 ans = 0;
  i64 now = -1e18;
  vector<i64> t(n), s(n);
  for (i64 i = 0; i < n; i++) cin >> t[i];
  for (i64 i = 0; i < n; i++) cin >> s[i];
  for (i64 i = 0; i < n; i++) {
    if (s[i] < now) continue;
    ans++;
    now = t[i] + s[i];
  }
  cout << ans << "\n";
}