#include <bits/stdc++.h>
#include "peru.h"
using namespace std;

const long long MOD = 1e9 + 7;
// const long long MOD = 998244353;
const long long OO = 1e10, N = 1e5 + 5, LOG = 20;

#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)

#define popCnt(x) (__builtin_popcountll(x))
#define int long long
#define ll long long
#define F  first
#define S  second
#define double long double
#define pi  M_PI
#define all(x) x.begin() , x.end()

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};


void add (int val, int idx, deque<pair<int, int>> &d)
{
    while(!d.empty() && d.front().first <= val)d.pop_front();
    d.push_front({val, idx});
}

void del(int idx, deque<pair<int, int>> &d)
{
    if(!d.empty() && d.back().second == idx)d.pop_back();
}



int power(long long x, unsigned int y)
{
    long long p = MOD;
    int res = 1;
    x = x % p;
    if (x == 0) return 0;
    while (y > 0)
    {
        if (y & 1)
            res = (res * x) % p;
        y = y >> 1;
        x = (x * x) % p;
    }
    return res;
}

int add(int a, int b)
{
    return ((a % MOD) + (b % MOD)) % MOD;
}
int mul(int a, int b)
{
    return ((a % MOD) * (b % MOD)) % MOD;
}


int solve(int N, int K, int *S)
{
    deque<pair<int, int>>d;

    int ans[N] = {};

    for (int i = 0; i < K; ++i)
    {
        add(S[i], i, d);
        ans[i] = d.back().first;
    }

    for (int i = K; i < N; ++i)
    {
        del(i - K, d);
        add(S[i], i, d);
        ans[i] = d.back().first + ans[i - K];
    }
    int x = 0;
    for (int i = 0; i < N; ++i)
    {
        x = add(x, mul(ans[i], power(23, N - i - 1)));
    }
    return x;
}


signed main()
{
    fast;

// #ifndef ONLINE_JUDGE
//     freopen("input.txt", "r", stdin);
//     freopen("Output.txt", "w", stdout);
// #endif


    int t = 1;
    // cin >> t;
    for (int tct = 1; tct <= t; tct++)
    {

        int n ;
        cin >> n;
        int k;
        cin >> k;

        int a[n];
        for (int i = 0; i < n; ++i)
        {
            cin >> a[i];
        }


        cout << solve(n,  k, a) << endl;








    }
}

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;
      |                          ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccUcAXeF.o: in function `main':
answer.code:(.text.startup+0x0): multiple definition of `main'; /tmp/ccsE01AE.o:implementer.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccsE01AE.o: in function `main':
implementer.cpp:(.text.startup+0x151): undefined reference to `solve(int, int, int*)'
collect2: error: ld returned 1 exit status