//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);
});
