import java.io.*;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class Main {
    static int[] values;
    static List<Map<Integer, Integer>> dp = new ArrayList<>();
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        values = new int[n];
        for (int i = 0; i < n; i++) {
            values[i] = sc.nextInt();
            dp.add(new HashMap<>());
        }
        Arrays.sort(values);
        System.out.println(dfw(n - 1, k));
    }
    
    static int dfw(int idx, int v) {
        if (idx == 0) {
            return v % values[idx];
        }
        if (!dp.get(idx).containsKey(v)) {
            dp.get(idx).put(v, Math.max(dfw(idx - 1, v), dfw(idx - 1, v % values[idx])));
        }
        return dp.get(idx).get(v);
    } 
}
class Scanner {
    BufferedReader br;
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
        } catch (Exception e) {
            
        }
    }
    
    public int nextInt() {
        return Integer.parseInt(next());
    }
    
    public long nextLong() {
        return Long.parseLong(next());
    }
    
    public double nextDouble() {
        return Double.parseDouble(next());
    }
    
    public String next() {
        try {
            while (!st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            return st.nextToken();
        }
    }
    
}