#include <algorithm>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main() {
  int n, pos;
  int a[100000];
  int count = 0;
  cin >> n;
  for (int ni = 0; ni < n; ++ni) {
    cin >> a[ni];
  }
  pos = n - 1;
  for (int len = n; len > 0; --len) {
    while (pos >= 0) {
      if (a[pos] == len) {
        --pos;
        break;
      }
      --pos;
      ++count;
    }
  }
  cout << count << endl;
  return 0;
}