#include <stdio.h>
#include <stdlib.h>

int check(int[7][7], int, int);
void swap(int*, int*);

int main(int argc, const char * argv[]) {
  int i, j, n;
  int s[7][7];
  char d[7];

  scanf("%d", &n);
  for (j = 0; j < n; j++) {
    scanf("%s", d);
    for (i = 0; i < n; i++) {
      if (d[i] == '-')
        s[j][i] = 0;
      else if (d[i] == 'x')
        s[j][i] = -1;
      else if (d[i] == 'o')
        s[j][i] = 1;
      else
        s[j][i] = 9;
    }
  }

  i = check(s, n, 1);
  j = check(s, n, -1);

  if (i < j)
    printf("%d\n", i);
  else
    printf("%d\n", j);

  return EXIT_SUCCESS;
}

int check(int d[7][7], int n, int a) {
  int i, j, z, r = 1;
  int c[7][7], num[7] = {0, 0, 0, 0, 0, 0, 0};

  for (j = 0; j < n; j++) {
    for (i = 0; i < n; i++) {
      c[j][i] = d[j][i];
      if (d[j][i] == 0) {
        if (j < i)
          c[j][i] = a;
        else
          c[j][i] = -a;
      }
    }
  }

  for (j = 0; j < n; j++)
    for (i = 0; i < n; i++)
      if (c[j][i] == 1)
        num[j]++;
  z = num[0];

  for (j = 0; j < n -1; j++)
    for (i = j + 1; i < n; i++)
      if (num[j] < num[i])
        swap(&num[j], &num[i]);

  i = num[0];
  for (j = 1; j < n; j++) {
    if (num[j] == z)
      break;
    if (num[j] < i) {
      r++;
      i = num[j];
    }
  }

  return r + 1;
}

void swap(int *a, int *b) {
  int c = *a;
  *a = *b;
  *b = c;
}