#include <bits/stdc++.h>
#include <random>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
//#define int ll
//#define int __int128
//#define ll __int128
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector< vi > vvi;
typedef vector< vvi > vvvi;
typedef vector<bool> vb;
typedef vector< vb > vvb;
typedef vector< vvb > vvvb;
typedef vector<short> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<ld> vld;
typedef vector<vld> vvld;
typedef vector<vvld> vvvld;
typedef vector<string> vst;
typedef vector<vst> vvst;
typedef pair<ld, ld> pld;
typedef complex<double> base;

#define inmin(a, b) a = min(a, (b))
#define inmax(a, b) a = max(a, (b))
#define ALL(a) a.begin(),a.end()
#define RALL(a) a.rbegin(),a.rend()
#define sqr(x) ((x) * (x))
#define fori(i, n) for(int i = 0; i < int(n); ++i)
#define SZ(a) ((int)((a).size()))
#define triple(T) tuple<T, T, T>
#define quad(T) tuple<T, T, T, T>
#define watch(x) cerr << (#x) << " = " << (x) << endl;

#ifdef MAX_HOME
#define cerr cout
#else
#define cerr if (false) cerr
#endif

const double PI = 2 * acos(0.0);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng_64(chrono::steady_clock::now().time_since_epoch().count());

const string DIGITS = "0123456789";
const string ALPH = "abcdefghijklmnopqrstuvwxyz";

template <class T0, class T1>
inline ostream & operator << (ostream &out, pair<T0, T1> &a) {
    return out << "{" << a.first << ", " << a.second << "}";
}

template <class T0, class T1, class T2>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << "}";
}

template <class T0, class T1, class T2, class T3>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2, T3> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << ", " <<  get<3>(a) << "}";
}

template<class T>
inline ostream & operator << (ostream &out, vector<T> &a) {
    out << "[";
    fori (i, a.size())
        out << a[i] << vector<string>{", ", "]  "}[i + 1 == a.size()];
    return out;
}



void smain();

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

#ifdef MAX_HOME
    freopen("input.txt", "r", stdin);
    clock_t start = clock();
#endif
    cout << setprecision(12) << fixed;
    smain();
#ifdef MAX_HOME
    cout << "\n\n\n\nTOTAL EXECUTION TIME: " << float( clock () - start ) /  CLOCKS_PER_SEC << endl;
#endif
    return 0;
}

typedef bitset<2000010> bs;

int n, m;
vvi dp;
bs mat;
const int L = 22;
bs cnt[L];
void smain() {

    cin >> n >> m;
    dp.resize(n + 1, vi(m + 1, 0));
    for (int i = 1; i <= n; ++i) {
        string s;
        cin >> s;
        for (int j = 1; j <= m; ++j) mat[i * (m + 1) + j] = s[j - 1] == '1';
    }
//    cnt.resize(L, vvb(n + 1, vb(m + 1, 0)));

    fori (p, L) {
        cnt[p] = mat;
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= m; ++j) {
                if (i > (1 << p))
                    cnt[p][i * (m + 1) + j] = cnt[p][i* (m + 1) +j] ^
                                                  cnt[p][(i - (1 << p))* (m + 1) +j];
                if (j > (1 << p))
                    cnt[p][i* (m + 1) +j] = cnt[p][i* (m + 1) +j] ^
                                                cnt[p][i* (m + 1) +j - (1 << p)];
                if (i > (1 << p) && j > (1 << p))
                    cnt[p][i* (m + 1) +j] = cnt[p][i* (m + 1) +j] ^
                                                cnt[p][(i - (1 << p)) * (m + 1) +j - (1 << p)];
            }
        }
    }
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            int ans = max(dp[i - 1][j], dp[i][j - 1]);
            int res = mat[i* (m + 1) +j];
            if (ans < L) {
                res ^= cnt[ans][i* (m + 1) +j];
            } else {
                res = 0;
            }
            dp[i][j] = ans + res;
        }
    }
    vi a = {1};
    fori (i, dp[n][m]) {
        vi nx;
        int c = 0;
        for (int j = 0; j < a.size(); ++j) {
            c += a[j] * 2;
            nx.push_back(c % 10);
            c /= 10;
        }
        if (c) nx.push_back(c);
        a = nx;
    }
    for (int i = (int)a.size() - 1; i >= 0; --i) {
        cout << a[i];
    }

}