#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 10;
const long long inf = 1e18 + 10;
struct node {
  int kt;
  int len;
} p[maxn];
int vis[maxn];
int main() {
  int i, j;
  ios::sync_with_stdio(0);
  int n;
  while (cin >> n) {
    for (i = 1; i <= n; i++) {
      cin >> p[i].len;
      p[i].kt = 1;
    }
    memset(vis, 0, sizeof(vis));
    int pre = 1e9 + 10;
    int flag = 0;
    int cnt = 1;
    for (i = n - 1; i >= 1; i--) {
      pre = min(pre, i + 1 - p[i + 1].len);
      if (pre > i) cnt++;
    }
    cout << cnt << endl;
  }
  return 0;
}
