Maximize dot product

//Maximize dot product

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

class GfG {
    public static void main(String args[]) {
            Scanner sc = new Scanner(System.in);
            int t = sc.nextInt();

            while(t-- > 0) {
                    int n = sc.nextInt();
                    int m = sc.nextInt();
                    int a[] = new int[n];
                    int b[] = new int[m];

                    for(int i = 0; i < n; i++)
                        a[i] = sc.nextInt();

                    for(int i = 0; i < m; i++)
                        b[i] = sc.nextInt();

                    Solution ob = new Solution();
                    System.out.println(ob.maxDotProduct(n, m, a, b));
                }
        }
}    

class Solution {
    int help(int i, int j, int n, int m, int a[], int b[], int dp[][], int diff) {
	    if(i == n || j == m) {
	        return 0;
	    }
	    
	    if(dp[i][j] != -1) {
	        return dp[i][j];
	    }
	    
	    int sum1 = 0, sum2 = 0;
	    
	    if(diff != 0) {
	        sum1 = help(i + 1, j, n, m, a, b, dp, diff - 1);
	    }
	    
	    sum2 = a[i] * b[j] + help(i + 1, j + 1, n, m, a, b, dp, diff);
	    
	    return dp[i][j] = Math.max(sum1, sum2);
	}
	
	public int maxDotProduct(int n, int m, int a[], int b[]) {
		int dp[][] = new int[n][m];
		
		for(int temp[] : dp) {
		    Arrays.fill(temp, -1);
		}
		
		return help(0, 0, n, m, a, b, dp, n - m);
	} 
}