#include <bits/stdc++.h> using namespace std; #define forn(i, n) for(ll i = 0; i < (n); ++i) #define for1(i, n) for(ll i = 1; i <= (n); ++i) #define chmin(a, b) ((a) = min(a, b)) #define dbg(x) cout << #x << " = " << (x) << endl; using ll = long long; const int oo = 1e7; const int MAXN = 2e5 + 2; ll n, m; int a[MAXN]; #define mret return mem[i] = int mem[MAXN]; int f(int i) { if (i == -1) return 0; if (mem[i] != -1) return mem[i]; int ans = oo; for (int j = i; j >= 0; --j) if (a[j] - j * m >= a[i + 1] - (i + 1) * m) chmin(ans, f(j - 1) - j); mret i + ans; } int main() { cin >> n >> m; for1(i, n) cin >> a[i]; forn(i, n+2) mem[i] = -1; // forn(i, n+1) f(i); cout << f(n); }