#include <bits/stdc++.h>
using namespace std;
const int mxN = 2e5+2;
int bit[mxN];
void umax(int idx, int x) {
for (; idx < mxN; idx |= idx+1) {
bit[idx] = max(bit[idx], x);
}
}
int qmax(int idx) {
int s = 0;
for (; idx >= 0; idx = (idx & (idx + 1)) - 1) {
s = max(s, bit[idx]);
}
return s;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<int> a(n+1), c;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
a[i] = m*i - a[i];
c.push_back(a[i]);
}
sort(c.begin(), c.end());
c.erase(unique(c.begin(), c.end()), c.end());
auto find = [&](int x) {
return lower_bound(c.begin(), c.end(), x) - c.begin();
};
vector<int> dp(n+1, -1e9);
int ans = 0;
for (int i = 1; i <= n; ++i) {
if (a[i] < 0) continue;
dp[i] = qmax(find(a[i])) + 1;
umax(find(a[i]), dp[i]);
ans = max(ans, dp[i]);
}
cout << n-ans << '\n';
}
