// compile: g++ -o data data.cpp -std=gnu++20 -DLOCAL
// run: ./data < data.in
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#endif
#define PV(v) for (int i=0;i<v.size();++i)cout<<v[i]<<" ";cout<<endl;
#define int long long
#define MAXN 200010

using namespace std;

int n, k, a[MAXN];
vector<int> odd[MAXN];
vector<int> even[MAXN];
vector<pair<int, int>> v;

int total(vector<int> &h, int p) {
    // >p
    // <p+k
    int rad = k / 2;
    int cL = max(p, 2*rad - p - 2), cR = min(p + k, 2 * (n-rad) - p);
    int l = 0, r = (int)(h.size()) - 1;
    int L = -1, R = -1;
    while (l <= r) {
        int mid = l + (r - l) / 2;
        if (h[mid] <= cL) l = mid + 1;
        else {
            L = mid;
            r = mid - 1;
        }
    }
    l = 0, r = (int)(h.size()) - 1;
    while (l <= r) {
        int mid = l + (r - l) / 2;
        if (h[mid] >= cR) r = mid - 1;
        else {
            R = mid;
            l = mid + 1;
        }
    }
    // cout << "#" << p << endl;
    if (!~L || !~R || L > R) return 0;
    // for (int i = L; i <= R; ++i) cout << h[i] << " "; cout << endl;
    // for (int i = L; i <= R; ++i) v.push_back(make_pair(p, h[i]));
    return R - L + 1;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    cin >> n >> k;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        if (i & 1) odd[a[i]].push_back(i);
        else even[a[i]].push_back(i);
    }
    int cnt = 0;
    for (int i = 0; i < n; ++i) {
        cnt += total((i & 1) ? odd[a[i]] : even[a[i]], i);
    }
    // for (int i = 0; i < v.size(); ++i) {
    //     cout << v[i].first << " " << v[i].second << endl;
    // }

    // cout << cnt << endl;
    cout << (n-k+1) * (k/2) - cnt << endl;
    // cout << (n-k+1) * (k/2) << endl;

    return 0;
}