Algorithm

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 */
//package kisa53;

import java.util.Scanner;

/**
 *
 * @author reetta
 */
public class Kisa53 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        
        int[] a = new int[n];
        int[] b = new int[n];
        
        for (int i = 0; i < n; i++) {
            a[i] = scan.nextInt();
        }
        for (int i = 0; i < n; i++){
            b[i] = scan.nextInt();
        }
        
        long res = 0;
        for(int i = 0; i < n; i++){
            res += a[i]*b[i];
        }
        
        System.out.println(res);
        
    }
    
//    long f(int i, int j, long a[], long b[], int n) {
//    if (i >= n) return 0;
//    swap(a[i],a[j]);
//    long r = a[i]*b[i] + f(i+1,i+1,b,a,n);
//    swap(a[i],a[j]);
//    if (j < n-2) {
//        r = min(r, f(i,j+2,a,b,n));
//    }
//    return r;

    
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER