#include <algorithm>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>


using namespace std;


using ull = unsigned long long;
using ll = long long;
using ld = long double;


#define all(v) v.begin(), v.end()
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define rep2(i, n, m) for (ll i = n; i <= m; ++i)
#define rep3(i, n, m) for (ll i = n; i >= m; --i)


template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>;
template<class T> using pq  = priority_queue<T>;


template<class S, class T> inline bool chmax(S &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class S, class T> inline bool chmin(S &a, T b) { if (a > b) { a = b; return true; } return false; }


constexpr int INF = 1e9;


int n;
vector<int> a;


int main() {
  cin >> n;
  a.resize(n);

  vector<int> dp(n+1, 0);
  rep(i, n) cin >> a[i];

  rep(i, n) dp[a[i]] = dp[a[i]-1] + 1;
  int cnt = *max_element(all(dp));

  cout << n - cnt << endl;
  return 0;
}