import java.awt.*;
import java.io.*;
import java.math.*;
import java.util.*;
 
public class Main{
    FastScanner in;
    PrintWriter out;
 
    public void solve() {
        int n = in.nextInt();
        int m = in.nextInt();
 
        long[] fact = new long[m];
        fact[0] = 1;
        for (int i = 1; i < m; i++)
            fact[i] = (fact[i - 1] * i) % m;
 
        int ans = 0;
        for (int i = 0; i < n; i++) {
            long x = in.nextLong();
            long r = x % m;
            if (x % 2 == 0) {
                r *= (x / 2) % m;
                r %= m;
                r *= (x + 1) % m;
                r %= m;
            }
            else {
                r *= x % m;
                r %= m;
                r *= ((x + 1) / 2) % m;
                r %= m;
            }
            if (x+1 < m) {
                r += fact[(int)x + 1];
                r %= m;
            }
            r = (r + m - 1) % m;
            ans += r;
            ans %= m;
        }
        out.println(ans);
    }
 
    public void run()
    {
        in = new FastScanner();
        out = new PrintWriter(System.out);
 
        solve();
 
        out.close();
    }
 
 
 
    public static void main(String[] args) {
        new Main().run();
    }
 
    class FastScanner {
        BufferedReader br;
        StringTokenizer st;
 
        FastScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt() {
            return Integer.parseInt(next());
        }
 
        long nextLong() {
            return Long.parseLong(next());
        }
 
        double nextDouble() {
            return Double.parseDouble(next());
        }
    }
}