import java.io.IOException;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
    static Scanner in = new Scanner(System.in);
    static int n = in.nextInt();
    static int[][] a = new int[n + 1][n + 1];
    static int[] color = new int[n + 1];
    static int k = 1;
    static final int black = 2;
    static final int grey = 1;
    static final int white = 0;
    static boolean f = true;

    public static void dfs(int v, int p) {
        if (color[v] == grey) {
            f = false;
        } else {
            color[v] = grey;

            for (int i = 1; i < n + 1; i++) {
                if (a[v][i] == 1 && color[i] != black && i != p) {
                    dfs(i, v);
                }
            }
            color[v] = black;
        }
    }


    public static void main(String[] args) {
        for (int i = 1; i < n + 1; i++) {
            for (int j = 1; j < n + 1; j++) {
                a[i][j] = in.nextInt();
            }
        }
        for (int i = 1; i < n + 1; i++) {
            color[i] = white;
        }

        dfs(1, -1);

        for (int i = 1; i < n + 1; i++) {
            if (color[i] != black) {
                f = false;
                break;
            }
        }
        if (f) System.out.println("YES");
        else System.out.println("NO");
    }

}