#include <bits/stdc++.h>
using namespace std;
ifstream fcin(".in");
ofstream fcout(".out");

const int N = 1e3 + 5;
const int baza = 16661;
const int mod = 1e9 + 7;
int v[N][N], h1[N], h2[N];
int n, m;

int fexp(int b, int e)
{
    if (e == 0)
        return 1;
    int r = fexp(b, e / 2);
    if (e % 2 == 0)
        return 1ll * r * r % mod;
    else
        return 1ll * r * r % mod * b % mod;
}

int main()
{
    fcin >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            fcin >> v[i][j];
    for (int j1 = 1; j1 < m; j1++)
    {
        for (int i = 1; i <= n; i++)
        {
            h1[i] = v[i][j1];
            h2[i] = v[i][j1 + 2];
        }
        int l = 0;
        for (int j2 = j1 + 2, p = 1; j2 <= m; j2 += 2, p++)
        {
            for (int i = 1; i <= n; i++)
                if (h1[i] == h2[i])
                    l++;
                else
                    l = 0;
            for (int i = 1; i <= n; i++)
            {
                h1[i] = (h1[i] + 1ll * fexp(baza, p) * v[i][p + j1]) % mod;
                h2[i] = ((h2[i] - 1ll * v[i][p + j1 + 1] * fexp(baza, p)) % mod +
                        (1ll * baza * v[i][j2]) % mod) % mod;
            }
        }
    }
    return 0;
}