#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cctype>

#include <algorithm>
#include <random>
#include <bitset>
#include <queue>
#include <functional>
#include <set>
#include <map>
#include <vector>
#include <chrono>
#include <iostream>
#include <limits>
#include <numeric>

#define LOG(FMT...) fprintf(stderr, FMT)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template <class T>
istream& operator>>(istream& is, vector<T>& v) {
  for (T& x : v)
    is >> x;
  return is;
}

template <class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
  if (!v.empty()) {
    os << v.front();
    for (int i = 1; i < v.size(); ++i)
      os << ' ' << v[i];
  }
  return os;
}

const int N = 110;

int a[N][N];
int x[N][N];

pair<int, int> ways[N * N];

int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }

int main() {
#ifdef ELEGIA
  freopen("test.in", "r", stdin);
  int nol_cl = clock();
#endif
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int n, m;
  cin >> n >> m;
  int sum = 0, rg = 0, cg = 0;
  for (int i = 0; i < n; ++i)
    for (int j = 0; j < m; ++j) {
      cin >> a[i][j];
      sum += a[i][j];
    }
  for (int i = 0; i < n; ++i) {
    int s = 0;
    for (int j = 0; j < m; ++j)
      s += a[i][j];
    rg = gcd(rg, s);
  }
  for (int j = 0; j < m; ++j) {
    int s = 0;
    for (int i = 0; i < n; ++i)
      s += a[i][j];
    cg = gcd(cg, s);
  }
  for (int i = 0; i <= n; ++i)
    for (int j = m; j; --j)
      a[i][j] -= a[i][j - 1];
  for (int i = n; i; --i)
    for (int j = 0; j <= m; ++j)
      a[i][j] -= a[i - 1][j];
  int cnt = 0;
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= m; ++j)
      if (rg % j == 0 && cg % i == 0)
        ways[++cnt] = make_pair(i, j);
  auto check = [&](int u, int v) {
    memcpy(x, a, sizeof(x));
    for (int i = 0; i <= n; ++i)
      for (int j = v; j <= m; ++j)
        x[i][j] += x[i][j - v];
    for (int j = 0; j <= m; ++j)
      for (int i = u; i <= n; ++i)
        x[i][j] += x[i - u][j];

    for (int i = 0; i <= n; ++i)
      for (int j = 0; j <= m; ++j) {
        if (i <= n - u && j <= m - v) {
          if (x[i][j] < 0)
            return false;
        } else if (x[i][j])
          return false;
      }
    return true;
  };
  sort(ways + 1, ways + cnt + 1, [&](const pair<int, int>& lhs, const pair<int, int>& rhs) { return lhs.first * lhs.second > rhs.first * rhs.second; });
  for (int i = 1; i <= cnt; ++i)
    if (check(ways[i].first, ways[i].second)) {
      cout << (sum / ways[i].first / ways[i].second);
      break;
    }

#ifdef ELEGIA
  LOG("Time: %dms\n", int ((clock()
          -nol_cl) / (double)CLOCKS_PER_SEC * 1000));
#endif
  return 0;
}