Magic Square Checker

You are given a N x N matrix of integers. Your task is to determine if it forms a magic square. A magic square is defined as a square matrix in which the sum of every row, every column, and both main diagonals are equal. Print 'YES' if it is a magic square and 'NO' otherwise. The first line of input contains the integer N, followed by N lines of N space-separated integers each. Example: Input: 3 8 1 6 3 5 7 4 9 2 Output: YES