process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function printShortestPath(n, i_start, j_start, i_end, j_end) {
    //  Print the distance along with the sequence of moves.
    var current = [j_start, i_start];
    var goal = [j_end, i_end];
    
    var moves = 0;
    
    while (isAbove(current, goal) && current[1]-goal[1]>1)
    {
        // is the goal above the knight
        if (isAbove(current, goal))
        {
            current[1] = current[1] - 2;
            // is the goal to the left
            if (isLeft(current, goal))
            {
                current[0] = current[0] - 1;
                moves++;
            }
            // the goal is to the right
            else if (isRight(current, goal))
            {
                current[0] = current[0] + 1;
                moves++;
            }
        }
    }
    
    /*
    while (isRight(current, goal) && goal[0]-current[0]>1)
    {
        // is the goal directly right of the knight
        if (isRight(current, goal))
        {
            current[0] = current[0] + 2;
            moves++;
        }
    }
    
    while (isBelow(current, goal) && goal[1]-current[1]>1)
    {
        // is the goal below the knight
        if (isBelow(current, goal))
        {
            current[1] = current[1] + 2;
            // is the goal to the right
            if (isRight(current, goal))
            {
                current[0] = current[0] + 1;
                moves++;
            }
            // the goal is to the left
            else if (isLeft(current, goal))
            {
                current[0] = current[0] - 1;
                moves++;
            }
        }
    }
    
    while (isLeft(current, goal) && current[0]-goal[0]>1)
    {
        // is the goal directly left of the knight
        if (isLeft(current, goal))
        {
            current[0] = current[0] - 2;
            moves++;
        }
    }
    */
    // has goal been reached
    if (current[0] == goal[0] && current[1] == goal[1])
    {
        console.log(moves);
    }
    else
    {
        console.log("Impossible");
        //console.log(current);
    }
}

function isLeft (current, goal)
{
    if(current[0]<goal[0])
    {
        return true;
    }
}

function isRight (current, goal)
{
    if(current[0]>goal[0])
    {
        return true;
    }
}

function isAbove (current, goal)
{
    if(current[1]>goal[1])
    {
        return true;
    }
}

function isBelow (current, goal)
{
    if(current[1]<goal[1])
    {
        return true;
    }
}

function main() {
    var n = parseInt(readLine());
    var i_start_temp = readLine().split(' ');
    var i_start = parseInt(i_start_temp[0]);
    var j_start = parseInt(i_start_temp[1]);
    var i_end = parseInt(i_start_temp[2]);
    var j_end = parseInt(i_start_temp[3]);
    printShortestPath(n, i_start, j_start, i_end, j_end);

}