revision diagonal sums

//also use arr.reverse
function processData(input) {

    let arr = input.split("\n");
    let new_arr = []
    let n = Number(arr[0])
    let sum1  = 0
    let sum2  = 0
    arr.shift()
    arr.forEach(element => new_arr.push(element.split(" ").map(Number)));
    for (let i = 0; i < new_arr.length; i++) {
        for (let j = 0; j < new_arr[i].length; j++) {
            if (i==j) {
              
                sum1 += new_arr[i][j]
               
            }
            if(i+j == new_arr[i].length -1 ){
                
                sum2 += new_arr[i][j]
               
            }
            
        }
        
    }
    console.log(Math.abs(sum1 - sum2));
    console.log(new_arr);
    
}


  
            
process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
    processData(_input);
});