#include <iostream>
using namespace std;
int ans[100001], n, inp, max_ans;
int main(){
    cin >> n;
    for(int i=0; i<n; ++i){
        cin >> inp;
        ans[inp] = ans[inp-1] + 1;
    }
    for(int i=1; i<=n; ++i){
        max_ans = max(max_ans, ans[i]);
    }
    cout << n - max_ans << endl;
}