#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>
#include <queue>
#include <complex>
  
#define INF 100000000
#define mod7 10000000007
#define YJ 1145141919
#define INF_INT_MAX 2147483647
#define INF_LL_MAX 9223372036854775807
#define INF_LL 9223372036854775
#define EPS 1e-10
#define Pi acos(-1)
#define LL long long
#define ULL unsigned long long
#define LD long double 
 
using namespace std;

#define MAX_N 100005

int N;
int A[MAX_N];

int main(){

  cin >> N;
  for(int i = 0; i < N; i++){
    cin >> A[i];
  }

  int ans = N;
  int nextNum = N;
  for(int i = N-1; 0 <= i; i--){
    if(A[i] == nextNum){
      ans--;
      nextNum--;
    }
  }

  cout << ans << endl;

  return 0;

}