#include <iostream>
using namespace std;

int main() {
    int b[1000000];
    int n;
    cin >> n;
    int xn = n;
    int cnt = 0;

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

    for (int i = n-1; i>=0; i--) {
        if (b[i]==xn) {
            cnt++;
            xn--;
        }
    }

    cout << n-cnt << endl;

    return 0;
}