char S[501][501];
int H[501][501];
int Px[501];
int Py[501];
int H1[501][501];
int P1x[501];
int P1y[501];

int get_hash(int x1, int y1, int x2, int y2) {
    return ((1ll * H[x2][y2] - 1ll * H[x1 - 1][y2] * Px[x2 - x1 + 1] - 1ll * H[x2][y1 - 1] * Py[y2 - y1 + 1] + 1ll * H[x1 - 1][y1 - 1] *(1ll* Py[y2 - y1 + 1] * Px[x2 - x1 + 1] % MOD)) % MOD + MOD) % MOD;
}
int get_hash1(int x1, int y1, int x2, int y2) {
    return ((1ll * H1[x2][y2] - 1ll * H1[x1 - 1][y2] * P1x[x2 - x1 + 1] - 1ll * H1[x2][y1 - 1] * P1y[y2 - y1 + 1] + 1ll * H1[x1 - 1][y1 - 1] *(1ll* P1y[y2 - y1 + 1] * P1x[x2 - x1 + 1] % MOD1)) % MOD1 + MOD1) % MOD1;
}

bool check(int k, int n, int m, int& x1, int& y1, int& x2, int& y2) {
    unordered_map<ll, pair<int, int>> used;
    forn(i, 1, n - k + 2) {
        forn(j, 1, m - k + 2) {
            ll h = get_hash1(i, j, i + k - 1, j + k - 1) * ll(1e9) + 1ll * get_hash(i, j, i + k - 1, j + k - 1);
            if (used.contains(h)) {
                x1 = used[h].f;
                y1 = used[h].s;
                x2 = i;
                y2 = j;
                return true;
            }
            used[h] = {i, j};
        }
    }
    return false;
}

void solve(){
    int n, m;
    cin >> n >> m;
    forn1(i, 1, n) {
        forn1(j, 1, m) {
            cin >> S[i][j];
        }
    }
    H[0][0] = 0;
    forn1(i, 1, n) {
        H[i][0] = 0;
    }
    forn1(i, 1, m) {
        H[0][i] = 0;
    }
    forn1(i, 0, n) {
        Px[i] = (i == 0 ? 1 : Px[i - 1] * 1ll * 57 % MOD);
    }
    forn1(i, 0, m) {
        Py[i] = (i == 0 ? 1 : Py[i - 1] * 1ll * 41 % MOD);
    }
    forn1(i, 1, n) {
        forn1(j, 1, m) {
            H[i][j] = ((H[i - 1][j] * 1ll * 57 + H[i][j - 1] * 1ll * 41 - H[i - 1][j - 1] * 1ll * 57 * 41 + 1ll * (S[i][j] - 'a' + 1)) % MOD + MOD) % MOD;
        }
    }
    H1[0][0] = 0;
    forn1(i, 1, n) {
        H1[i][0] = 0;
    }
    forn1(i, 1, m) {
        H1[0][i] = 0;
    }
    forn1(i, 0, n) {
        P1x[i] = (i == 0 ? 1 : P1x[i - 1] * 1ll * 37 % MOD1);
    }
    forn1(i, 0, m) {
        P1y[i] = (i == 0 ? 1 : P1y[i - 1] * 1ll * 43 % MOD1);
    }
    forn1(i, 1, n) {
        forn1(j, 1, m) {
            H1[i][j] = ((H1[i - 1][j] * 1ll * P1x[1] + H1[i][j - 1] * 1ll * P1y[1] - H1[i - 1][j - 1] * 1ll * P1x[1] * P1y[1] + 1ll * (S[i][j] - 'a' + 1)) % MOD1 + MOD1) % MOD1;
        }
    }
    int mi = 0, ma = min(n, m) + 1;
    int x1;
    int y1;
    int x2;
    int y2;
    while(mi + 1 < ma) {
        int sr = (mi + ma) / 2;
        if (check(sr, n, m, x1, y1, x2, y2)) {
            mi = sr;
        } else {
            ma = sr;
        }
    }
    cout << mi << endl;
    if (mi != 0) {
        cout << x1 << ' ' << y1 << endl << x2 << ' ' << y2 << endl;
    }
}