#include <bits/stdc++.h>
using namespace std;
int n, sa[100005], rk[100005], w[100005][30], f[100005][27], maxn[30];
long long x;
inline int rd() {
	x =  (100000005 * x + 1532777326) % 998244353;
	return x / 100;
}
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n >> x;
	for (int i = 1; i <= n; i++) {
		cin >> sa[i];
		rk[sa[i]] = i;
	}
	rk[n + 1] = -1;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= 26; j++) {
			w[i][j] = rd() % 10000;
		}
	}
	for (int i = 1; i <= 26; i++) {
		f[1][i] = w[sa[1]][i];
		maxn[i] = max(maxn[i - 1], f[1][i]);
	}
	int op;
	maxn[0] = -0x3f3f3f3f;
	f[1][0] = -0x3f3f3f3f;
	for (int i = 2; i <= n; i++) {
		if (rk[sa[i] + 1] > rk[sa[i - 1] + 1]) op = 0;
		else op = 1;
		for (int j = 1; j <= 26; j++) {
			f[i][j] = maxn[j - op] + w[sa[i]][j];
		}
		for (int j = 1; j <= 26; j++) {
			maxn[j] = max(maxn[j - 1], f[i][j]);
		}
	}
	cout << maxn[26];
}