#include <bits/stdc++.h>

using namespace std;
ifstream fin("imagine.in");
ofstream fout("imagine.out");

int a[255][255], n;
int s[255][255];

void Citire()
{
    int i, j;
    fin >> n;
    for(i = 1; i <= n; i++)
        for(j = 1; j <= n; j++)
            fin >> a[i][j];
}

void Prelucrare()
{
    int i, j;
    for(i = 1; i <= n; i++)
        for(j = 1; j <= n; j++)
            s[i][j] = s[i-1][j] + s[i][j-1] + a[i][j] - s[i-1][j-1];
}

int Test(int l1, int c1, int l2, int c2)
{
    if(l1 == l2 && c1 == c2) return 2;
    int S, nr;
    S = s[l2][c2] - s[l1-1][c2] - s[l2][c1-1] + s[l1-1][c1-1];
    nr = (l2 - l1 +1) * (c2 - c1 +1);
    if(S == 0 || S == nr) return 2;
    int lm, cm;
    lm = (l1 + l2) / 2;
    cm = (c1 + c2) / 2;
    return 1 + Test(lm+1,c1,l2,cm) + Test(l1,c1,lm,cm) + Test(lm+1,cm+1,l2,c2) + Test(l1,cm+1,lm,c2);
}

int main()
{
    Citire();
    Prelucrare();
    fout<<Test(1, 1, n, n)<<"\n";
    fin.close();
    fout.close();
    return 0;
}