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package javaapplication7;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Scanner;
import java.util.Arrays;
import static java.util.Arrays.stream;
import java.util.LinkedList;

/**
 *
 * @author hilal
 */
public class JavaApplication7 {

    public static void main(String[] args) throws IOException { 
        
        LinkedList<String> ar = new LinkedList<>();
        
        try {
      File myObj = new File("deneme.txt");
      Scanner myReader = new Scanner(myObj);
      while (myReader.hasNextLine()) {
        String data = myReader.nextLine();
          ar.add(data);
      }

      myReader.close();
    } catch (FileNotFoundException e) {
      System.out.println("An error occurred.");
      e.printStackTrace();
    }
        int[][] array = new int[ar.size()][ar.size()];
        for(int i = 0; i < ar.size(); i++){
            for(int j = 0; j < ar.size(); j++){
                if(j > i){
                    array[i][j] = 0;
                }else{
                    if(ar.get(i).split(" ")[j] != null){
                        array[i][j] = Integer.parseInt(ar.get(i).split(" ")[j]);
                    }
                }
                    
                }
            }
       
        int sum = array[0][0];
        int max = 0;
        int index = 0;
        int index_y = 0;
        int old_index = 0;
        int old_index_y = 0;
        for (int i = 1; i < array[0].length; i++) {
            old_index = index;
            old_index_y = index_y;
            max = 0;
            for (int j = 0; j < array[0].length; j++) {
               
                if (array[i][j] > max && isPrime(array[i][j]) == false) {
                    max = array[i][j];
                    index = i;
                    index_y = j;   
                } 
            }
            if(old_index +1 == index && (index_y == old_index_y-1 || index_y == old_index_y+1)){
                sum+=max;
            }else{
                if(array[old_index+1][old_index_y-1]>array[old_index+1][old_index_y+1] && isPrime(array[old_index+1][old_index_y-1])==false){
                    sum += array[old_index+1][old_index_y-1];
                    index = old_index+1;
                    index_y = old_index_y-1;
                    
                }else{
                    if(isPrime(array[old_index+1][old_index_y+1])==false){
                    sum += array[old_index+1][old_index_y+1];
                    index = old_index + 1;
                    index_y = old_index_y+1;
                    }  
                }
            }
            
            
        }
        System.out.println(sum);
       
    }
    public static boolean isPrime(int N) {
        boolean ispr = true;
        if (N <= 1) {
            ispr = false;
        } 
            for (int i = 2; i <= N-1; i++) {
                if (N % i == 0) {
                    ispr = false;
                    break;
                }
            }
        
        return ispr;
    }

}