#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

int main()
{
	int n; cin >> n;
	vector<int> a(n); rep(i, 0, n) cin >> a[i];

	int i = n - 1;
	while (a[i] != n) i--;

	int cnt = 1;
	rrep(j, n - 1, 1)
	{
		while (a[i] != j)
		{
			i--;
			if (i < 0) break;
		}
		
		if (i < 0) break;
		cnt++;
	}
	//cnt--;

	cout << n - cnt << endl;
}