#include <bits/stdc++.h>
#include <peru.h>
using namespace std;
typedef long long ll;
const int MAXN = 2500000;
const int MOD = 1e9 + 7;
int add (int a, int b) {
a += b; if (a >= MOD) a -= MOD;
return a;
}
int sub (int a, int b) {
a -= b; if (a < 0) a += MOD;
return a;
}
int mul (int a, int b) {
return (a * 1ll * b) % MOD;
}
int pw[MAXN + 25];
ll dp[MAXN + 25];
int solve (int n, int k, int *s) {
pw[0] = 1; for (int i = 1; i < MAXN + 25; i++) {
pw[i] = mul(23, pw[i - 1]);
}
int ret = 0;
for (int i = 1; i <= n; i++) {
int mx = 0;
dp[i] = 1e18;
for (int j = i - 1; j >= max(0, i - k); j--) {
mx = max(mx, s[j]);
dp[i] = min(dp[i], dp[j] + mx);
}
ret = add(ret, mul(pw[n - i], dp[i] % MOD));
}
return ret;
}
