#include <bits/stdc++.h>
using namespace std;
const int N = 2e5+1, inf = INT_MAX;
int n, m, a[N];
vector<int> suf, dp[2];
signed main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n >> m;
a[0] = 0;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
dp[0].clear();
dp[0].resize(1);
dp[0][0] = 0;
for (int i = 1; i <= n; i++) {
suf.clear();
suf.resize(m*(i-1) + 1);
suf[m*(i-1)] = dp[(i-1)%2][m*(i-1)];
for (int j = m*(i-1) - 1; j >= 0; j--) {
suf[j] = min(dp[(i-1)%2][j], suf[j+1]);
}
dp[i%2].clear();
dp[i%2].resize(m*i + 1);
for (int j = 0; j <= m*i; j++) {
dp[i%2][j] = suf[max(0, j-m)] + (j != a[i]);
}
}
int ans = inf;
for (int i = 0; i <= n*m; i++) {
ans = min(ans, dp[n%2][i]);
}
cout << ans << "\n";
}
