import java.util.ArrayList; import java.util.Arrays; import java.util.Scanner; class Main { public static void main(String[] args) { new Main().run(); } void run() { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int[][] f = new int[n][n]; for (int i = 0; i < n; ++i) { for (int j = 0; j < n; ++j) { f[i][j] = sc.nextInt(); } } int[] g = new int[1 << n]; Arrays.fill(g, -Integer.MAX_VALUE / 16); g[0] = 0; for (int s = 0; s < (1 << n); ++s) { if (Integer.bitCount(s) % 2 != 0) { continue; } int o = Integer.numberOfTrailingZeros(~s); for (int i = o + 1; i < n; ++i) { if (((1L << i) & s) > 0) { continue; } int ne = s | (1 << i) | (1 << o); g[ne] = Math.max(g[ne], g[s] + f[i][o]); } } System.out.println(g[(1 << n) - 1]); } static void tr(Object... objects) { System.out.println(Arrays.deepToString(objects)); } }