Pyramid

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Pyramid {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = Integer.parseInt(input.nextLine());
        ArrayList<Integer> sequence = new ArrayList<>();
        int previous = 0;
        for (int i = 0; i < n; i++){
            String[] row = clean(input.nextLine().split("[\\s]+"));
            if (i == 0){
                sequence.add(Integer.parseInt(row[0]));
                previous = Integer.parseInt(row[0]);
            }
            else {
                ArrayList<Integer> rowNums = new ArrayList<>();
                for (int j = 0; j < row.length; j++){
                    rowNums.add(Integer.parseInt(row[j]));
                }
                int currentNearest = Integer.MAX_VALUE;
                boolean found = false;
                for (int k = 0; k < rowNums.size(); k++){
                    if (rowNums.get(k) > previous && rowNums.get(k) <= currentNearest){
                        currentNearest = rowNums.get(k);
                        found=true;
                    }
                }
                if (found){
                    sequence.add(currentNearest);
                    previous = currentNearest;
                }
                else{
                    previous++;
                }
            }
        }
        for (int i = 0; i < sequence.size(); i++){
            if (i == sequence.size()-1){
                System.out.print(sequence.get(i) + "\n");
            }
            else {
                System.out.print(sequence.get(i) + ", ");
            }
        }
    }

    public static String[] clean(final String[] v) {
        List<String> list = new ArrayList<String>(Arrays.asList(v));
        list.removeAll(Collections.singleton(""));
        return list.toArray(new String[list.size()]);
    }
}