#define _CRT_SECURE_NO_WARNINGS
// #define _GLIBCXX_DEBUG
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <deque>
#include <complex>
#include <stack>
#include <queue>
#include <cstdio>
#include <cctype>
#include <cstring>
#include <ctime>
#include <iterator>
#include <bitset>
#include <numeric>
#include <list>
#include <iomanip>
#include <cassert>
#include <array>
#include <tuple>
#include <initializer_list>
#include <unordered_set>
#include <unordered_map>
#include <forward_list>
using namespace std;
typedef long long ll;
#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define all(c) begin(c), end(c)

using vi = vector<int>;
using vii = vector < vector<int>>;

int main() {
    int n;
    while (cin >> n) {
        vector<int> a(n);
        for (size_t i = 0; i < n; i++) {
            cin >> a[i];
        }
        int i = n - 1;
        int x = n;
        int ans = n;
        while (i >= 0) {
            if (a[i] == x) {
                --x;
                --ans;
            }
            --i;
        }
        cout << ans << endl;
    }
}