#include <bits/stdc++.h>

#define mp       make_pair
#define mt       make_tuple
#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
int N;
vector<int> A;
int main(){
  cin >> N;
  A.resize(N);
  for (auto &val : A){
    cin >> val;
  }
  int value = N;
  int result = 0;
  for (int i = N - 1; i >= 0; i--){
    if (value != A[i]){
      result++;
    }else{
      value--;
    }
  }
  cout << result << endl;
}