import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
public class Horse {

    private int[][] board;
    private int[] xer = { 2, 1, -1, -2, -2, -1, 1, 2 };
    private int[] yer = { 1, 2, 2, 1, -1, -2, -2, -1 };
    private final static int A_BIG_NUMBER = 10000;
    private final static int UPPER_BOUND = 64;


    public Horse(int n) {
        board =  new int[n][n];
    }

    private int solution(int x, int y, int destx, int desty, int move) {

        if(move == UPPER_BOUND) {
            /* lets put an upper bound to avoid stack overflow */
            return A_BIG_NUMBER;
        }

        if(x == 6 && y ==5) {
            board[6][5] = 1;
            return 1;
        }
        int min = A_BIG_NUMBER;
        for (int i = 0 ; i < xer.length; i++) {
            if (isMoveGood(x + xer[i], y + yer[i])) {
                if(board[x + xer[i]][y + yer[i]] != 0) {
                    min = Integer.min(min, 1 + board[x +xer[i]] [y +yer[i]]);                   
                } else {
                    min = Integer.min(min, 1 + solution(x + xer[i], y + yer[i], destx, desty, move + 1));   
                }                   
            }
        }   
        board[x][y] = min;
        return min;
    }


    private boolean isMoveGood(int x, int y) {
        if (x >= 0 && x < board.length && y >= 0 && y < board.length)
            return true;
        return false;
    }


     public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int i_start = in.nextInt();
        int j_start = in.nextInt();
        int i_end = in.nextInt();
        int j_end = in.nextInt();
        final Horse h = new Horse(n);
        int solution = h.solution(i_start, j_start, i_end, j_end, 0);
        if(solution == 10000){
            System.out.println("Impossible");
        }else{
            System.out.println(solution);
        }
        in.close();
    }
}