import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.FilterInputStream;
import java.io.BufferedInputStream;
import java.util.Collections;
import java.util.ArrayList;
import java.io.InputStream;

public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        ScanReader in = new ScanReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DCompression solver = new DCompression();
        solver.solve(1, in, out);
        out.close();
    }

    static class DCompression {
        int n;
        int[][] arr;

        public void solve(int testNumber, ScanReader in, PrintWriter out) {
            n = in.scanInt();
            arr = new int[n + 1][n + 1];


            for (int i = 1; i <= n; i++) {
                String str = in.scanString();
                int k = 1;
                for (int j = 0; j < n / 4; j++) {
                    int t[] = HEXtobiary(str.charAt(j));
                    for (int kk = 0; kk < 4; kk++) arr[i][k++] = t[kk];
                }
            }


            ArrayList<Integer> divisors = new ArrayList<>();
            for (int i = 1; i * i <= n; i++) {
                if (n % i == 0) {
                    divisors.add(i);
                    if (i * i != n) {
                        divisors.add(n / i);
                    }
                }
            }
            Collections.sort(divisors);

            int l = 0;
            int h = divisors.size() - 1;
            int ans = -1;
            while (l <= h) {
                int mid = (l + h) / 2;
                if (check(divisors.get(mid))) {
                    ans = mid;
                    l = mid + 1;
                } else {
                    h = mid - 1;
                }
            }


            if (ans == -1) {
                out.println();
            } else {
                out.println(divisors.get(ans));
            }
        }

        boolean check(int x) {
            int B[][] = new int[n / x + 1][n / x + 1];
            for (int[] kk : B) Arrays.fill(kk, -1);
            for (int i = 1; i <= n; i++) {
                for (int j = 1; j <= n; j++) {
                    int xx = (i % x == 0) ? i / x : i / x + 1;
                    int yy = (j % x == 0) ? j / x : j / x + 1;
                    if (B[xx][yy] == -1) {
                        B[xx][yy] = arr[i][j];
                    } else {
                        if (B[xx][yy] != arr[i][j]) return false;
                    }
                }
            }

            return true;

        }

        int[] HEXtobiary(char c) {
            if (c == '0') return new int[]{0, 0, 0, 0};
            if (c == '1') return new int[]{0, 0, 0, 1};
            if (c == '2') return new int[]{0, 0, 1, 0};
            if (c == '3') return new int[]{0, 0, 1, 1};
            if (c == '4') return new int[]{0, 1, 0, 0};
            if (c == '5') return new int[]{0, 1, 0, 1};
            if (c == '6') return new int[]{0, 1, 1, 0};
            if (c == '7') return new int[]{0, 1, 1, 1};
            if (c == '8') return new int[]{1, 0, 0, 0};
            if (c == '9') return new int[]{1, 0, 0, 1};
            if (c == 'A') return new int[]{1, 0, 1, 0};
            if (c == 'B') return new int[]{1, 0, 1, 1};
            if (c == 'C') return new int[]{1, 1, 0, 0};
            if (c == 'D') return new int[]{1, 1, 0, 1};
            if (c == 'E') return new int[]{1, 1, 1, 0};
            if (c == 'F') return new int[]{1, 1, 1, 1};
            return null;

        }

    }

    static class ScanReader {
        private byte[] buf = new byte[4 * 1024];
        private int INDEX;
        private BufferedInputStream in;
        private int TOTAL;

        public ScanReader(InputStream inputStream) {
            in = new BufferedInputStream(inputStream);
        }

        private int scan() {
            if (INDEX >= TOTAL) {
                INDEX = 0;
                try {
                    TOTAL = in.read(buf);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                if (TOTAL <= 0) return -1;
            }
            return buf[INDEX++];
        }

        public int scanInt() {
            int I = 0;
            int n = scan();
            while (isWhiteSpace(n)) n = scan();
            int neg = 1;
            if (n == '-') {
                neg = -1;
                n = scan();
            }
            while (!isWhiteSpace(n)) {
                if (n >= '0' && n <= '9') {
                    I *= 10;
                    I += n - '0';
                    n = scan();
                }
            }
            return neg * I;
        }

        public String scanString() {
            int c = scan();
            while (isWhiteSpace(c)) c = scan();
            StringBuilder RESULT = new StringBuilder();
            do {
                RESULT.appendCodePoint(c);
                c = scan();
            } while (!isWhiteSpace(c));
            return RESULT.toString();
        }

        private boolean isWhiteSpace(int n) {
            if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true;
            else return false;
        }

    }
}

