#if !defined(__clang__) && defined(__GNUC__)
#include <bits/stdc++.h>
#else
#include <cstdlib>
#include <climits>
#include <iostream>
#include <cstdint>
#include <vector>
#include <string>
#include <complex>
#include <bitset>
#include <queue>
#include <deque>
#include <stack>
#include <utility>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <regex>
#endif //  !defined(__clang__) && defined(__GNUG__)


using namespace std;

int main()
{
    int64_t N;
    std::cin >> N;

    std::vector<int64_t> A;
    for (decltype(N) i = 0; i < N; ++i) {
        int64_t t;
        std::cin >> t;
        A.push_back(t);
    }

    std::reverse(std::begin(A), std::end(A));

    int64_t v = N;
    int64_t count = 0;
    for (auto a: A) {
        if (a == v) {
            v--;
        }
        else {
            count++;
        }
    }

    std::cout << count << std::endl;

    return 0;
}