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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        long[] values = new long[n];
        HashSet<Long> type = new HashSet<>();
        for (int i = 0; i < n; i++) {
            values[i] = sc.nextLong();
            for (long j = 1; j <= Math.sqrt(values[i]); j++) {
                if (values[i] % j == 0) {
                    type.add(j);
                    type.add(values[i] / j);
                }
            }
        }
        long ans = 1;
        for (long x : type) {
            if (getCount(values, x) <= k) {
                ans = Math.max(ans, x);
            }
        }
        System.out.println(ans);
    }
    
    static long getCount(long[] values, long x) {
        long[] mod = new long[values.length];
        long[] minus = new long[values.length];
        for (int i = 0; i < values.length; i++) {
            mod[i] = values[i] % x;
        }
        Arrays.sort(mod);
        for (int i = 0; i < values.length; i++) {
            if (mod[i] > 0) {
                minus[i] = x - mod[i];
            }
            if (i > 0) {
                mod[i] += mod[i - 1];
            }
        }
        for (int i = values.length - 2; i >= 0; i--) {
            minus[i] += minus[i + 1];
        }
        long ans = Math.min(minus[0], mod[values.length - 1]);
        for (int i = 0; i < values.length - 1; i++) {
            ans = Math.min(ans, mod[i] + minus[i + 1]);
        }
        return ans;
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}