#include <fstream>
#include <iostream>
using namespace std;
int main()
{
    ifstream input("input.txt");
    int n = 0;
    input >> n;
    int** Matrix = new int*[n];
    for (int i = 0; i < n; i++) {
        Matrix[i] = new int[n];
    }
    //Read
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            input >> Matrix[i][j];
        }
    }
    //Find isolated vertices
    int res = 0;
    for (int i = 0; i < n; i++) {
        bool Flag = 0;
        for (int j = 0; j < n; j++) {
            if (j != i) {
                if (Matrix[i][j] > 0) Flag = 1;
            }
        }
        if (!Flag) res++;
    }
    cout << res;
}