#include "peru.h"
#include <bits/stdc++.h>

using namespace std;
using ll = long long;

constexpr int MOD = 1e9 + 7;
constexpr ll infLL = 3e18;

constexpr int N = 8e6 + 7;

namespace SegmentTree {
    ll t[N], tag[N];
    int sz = 1;

    void init(int n) {
        sz = 1 << __lg(n) + !!(n & (n - 1));
        t.assign(sz << 1, infLL);
        tag.assign(sz << 1, 0);
    }

    void apply(int x, ll tg) {
        t[x] += tg, tag[x] += tg;
    }

    void push(int x) {
        if (tag[x]) {
            apply(x << 1, tag[x]);
            apply(x << 1 | 1, tag[x]);
            tag[x] = 0;
        }
    }

    void pull(int x) {
        t[x] = min(t[x << 1], t[x << 1 | 1]);
    }

    void modify(int i, ll v, int x = 1, int lx = 0, int rx = sz) {
        if (lx + 1 == rx) {
            t[x] = v;
            return;
        }
        int mid = lx + rx >> 1;
        push(x);
        if (i < mid) {
            modify(i, v, x << 1, lx, mid);
        } else {
            modify(i, v, x << 1 | 1, mid, rx);
        }
        pull(x);
    }

    void rangeAdd(int l, int r, ll v, int x = 1, int lx = 0, int rx = sz) {
        if (l >= rx || lx >= r) {
            return;
        }
        if (l <= lx && rx <= r) {
            return apply(x, v);
        }
        int mid = lx + rx >> 1;
        push(x);
        rangeAdd(l, r, v, x << 1, lx, mid);
        rangeAdd(l, r, v, x << 1 | 1, mid, rx);
        pull(x);
    }

    ll rangeMin(int l, int r, int x = 1, int lx = 0, int rx = sz) {
        if (l >= rx || lx >= r) {
            return infLL;
        }
        if (l <= lx && rx <= r) {
            return t[x];
        }
        int mid = lx + rx >> 1;
        push(x);
        return min(rangeMin(l, r, x << 1, lx, mid), rangeMin(l, r, x << 1 | 1, mid, rx));
    }
};

ll dp[N];
int stk[N], top = 0;

int solve(int n, int k, int a[]){
    SegmentTree::init(n + 1);
    SegmentTree::modify(0, 0);
    int ans = 0;
    for (int i = 0; i < n; ++i) {
        while (top && a[stk[top - 1]] <= a[i]) {
            int l = top == 1 ? 0 : stk[top - 2] + 1;
            SegmentTree::rangeAdd(l, stk[top - 1] + 1, -a[stk[top - 1]]);
            --top;
        }
        stk[top++] = i;
        int l = top == 1 ? 0 : stk[top - 2] + 1;
        SegmentTree::rangeAdd(l, i + 1, a[i]);
        dp[i] = SegmentTree::rangeMin(max(0, i - k + 1), i + 1);
        SegmentTree::modify(i + 1, dp[i]);
        ans = (23LL * ans + dp[i]) % MOD;
    }
    return ans;
}

implementer.cpp: In function ‘char nextch()’:
implementer.cpp:15:31: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   15 |     if (pos == BUF_SIZE) fread(buf, BUF_SIZE, 1, fin), pos = 0;
      |                          ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
answer.code: In function ‘void SegmentTree::init(int)’:
answer.code:18:11: error: request for member ‘assign’ in ‘SegmentTree::t’, which is of non-class type ‘ll [8000007]’ {aka ‘long long int [8000007]’}
   18 |         t.assign(sz << 1, infLL);
      |           ^~~~~~
answer.code:19:13: error: request for member ‘assign’ in ‘SegmentTree::tag’, which is of non-class type ‘ll [8000007]’ {aka ‘long long int [8000007]’}
   19 |         tag.assign(sz << 1, 0);
      |             ^~~~~~