// Solution to "Zoo paths". The DFS was taken almost verbatim from the
// Wikipedia article on "Tarjan's strongly connected components algorithm".

import java.util.*;

// One node in the DFS:
class Node {
  int id; // input row #
  int index, low, comp; // DFS index, lowest reachable node, component #
  ArrayList<Integer> nbr; // edges
  boolean stack; // is this waiting to be labeled with a component #?

  public Node(int i) {
    id = i;
    index = -1;
    stack = false;
    low = -1;
    nbr = new ArrayList<Integer>();
    comp = -1;
  }
}

public class Zoo_bob {
  public static Scanner in;
  public static int n;
  public static int[][]p;
  public static Node[] nd;
  public static int index;
  public static int comp;
  public static Stack<Integer> stack;

  public static void main(String[] args) {
    in = new Scanner(System.in);
    n = in.nextInt();
    p = new int[n][n];
    nd = new Node[n];
    for (int i = 0; i < n; i++) {
      nd[i] = new Node(i);
      for (int j = 0; j < n; j++) {
        p[i][j] = in.nextInt();
        if (p[i][j] == 1) {
          nd[i].nbr.add(j);
        }
      }
    }

    stack = new Stack<Integer>();
    index = 0;
    comp = 0;
    for (int i = 0; i < n; i++) {
      if (nd[i].index == -1) {
        sc(i);
      }
    }

    int answer = 0;
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < n; j++) {
        if (i==j) continue;
        if (p[i][j]==1) continue;
        if (nd[i].comp >= nd[j].comp) answer++;
      }
    }
    System.out.println(answer);
  }

  public static void sc(int v) {
    nd[v].low = index;
    nd[v].index = index++;
    nd[v].stack = true;
    stack.push(v);
    for (Integer w:nd[v].nbr) {
      if (nd[w].index == -1) {
        sc(w);
        nd[v].low = Math.min(nd[v].low,nd[w].low);
      }
      else if (nd[w].stack) {
        nd[v].low = Math.min(nd[v].low,nd[w].index);
      }
    }
    if (nd[v].low == nd[v].index) {
      int w;
      do {
        w = stack.pop();
        nd[w].comp = comp;
        nd[w].stack = false;
      } while (w != v);
      comp++;
    }
  }
}