/* -*- coding: utf-8 -*-
 *
 * 3430.cc:  No.3430 Flip the Grid - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_H = 2000;
const int MAX_W = 2000;

/* typedef */

/* global variables */

int as[MAX_H][MAX_W];
int hs[MAX_H], vs[MAX_W];

/* subroutines */

/* main */

int main() {
  int h, w;
  scanf("%d%d", &h, &w);
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++) scanf("%d", as[i] + j);

  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++)
      hs[i] += as[i][j], vs[j] += as[i][j];

  int hos = 0;
  for (int i = 0; i < h; i++) hos += (hs[i] & 1);
  int vos = 0;
  for (int j = 0; j < w; j++) vos += (vs[j] & 1);

  printf("%d\n", max(hos, vos));
  
  return 0;
}