#define _USE_MATH_DEFINES #include <cstdio> #include <iostream> #include <sstream> #include <fstream> #include <iomanip> #include <algorithm> #include <cmath> #include <complex> #include <string> #include <vector> #include <array> #include <list> #include <queue> #include <stack> #include <set> #include <map> #include <bitset> #include <numeric> #include <limits> #include <climits> #include <cfloat> #include <functional> #include <iterator> using namespace std; const int INF = INT_MAX / 2; int longestIncreasingSubsequence(const vector<int>& a) { int n = a.size(); vector<int> dp(n, INT_MAX); for(int i=0; i<n; ++i){ vector<int>::iterator it = upper_bound(dp.begin(), dp.end(), a[i]); *it = a[i]; } return lower_bound(dp.begin(), dp.end(), INT_MAX) - dp.begin(); } int solve(const vector<int>& a) { int n = a.size(); vector<int> b(n+1, 0); for(int i=0; i<n; ++i){ b[i+1] = a[i] - i; if(b[i+1] <= 0) b[i+1] = -INF - i; } return n + 1 - longestIncreasingSubsequence(b); } int main() { int n; cin >> n; vector<int> a(n); for(int i=0; i<n; ++i) cin >> a[i]; cout << solve(a) << endl; return 0; }