import java.io.*;
import java.util.*;

public class Main implements Runnable {
	FastReader scn;
	PrintWriter out;
	String INPUT = "5040";

	void solve() {
		int n = scn.nextInt();
		int[][] arr = new int[n + 1][n + 1];
		for(int i = 1; i <= n; i++) {
			for(int j = 1; j <= n / 4; j++) {
				char ch = '0';
				int x = ch - '0';
				if(ch < '0' || ch > '9') {
					x = ch - 'A' + 10;
				}
				for(int k = 4 * (j - 1) + 1, p = 3; k <= 4 * j; k++, p--) {
					arr[i][k] = ((x >> p) & 1);
				}
			}
		}
		
		for(int i = 1; i <= n; i++) {
			for(int j = 1; j <= n; j++) {
				arr[i][j] += arr[i - 1][j] + arr[i][j - 1] - arr[i - 1][j - 1];
			}
		}
		
		int[] primes = linearSieve(n);
		int ans = 1;
		boolean[] fail = new boolean[n + 1];
		for(int i = 2; i <= n; i++) {
			if(fail[i]) {
				continue;
			}
			if(check(arr, i)) {
				ans = i;
				for(int j = i + 1; j <= n; j++) {
					if(j % i != 0) {
						fail[j] = true;
					}
				}
			} else if(Arrays.binarySearch(primes, i) >= 0){
				for(int j = 2 * i; j <= n; j += i) {
					fail[j] = true;
				}
			}
		}
		out.println(ans);
	}
	
	boolean check(int[][] arr, int k) {
		int n = arr.length, need = k * k;
		for(int i = k; i < n; i += k) {
			for(int j = k; j < n; j += k) {
				int sum = arr[i][j] - arr[i - k][j] - arr[i][j - k] + arr[i - k][j - k];
				if(sum != 0 && sum != need) {
					return false;
				}
			}
		}
		
		return true;
	}
	
	int[] linearSieve(int n) {
		boolean[] composites = new boolean[n + 1];
		int[] prime = new int[n + 1];
		int k = 0;
		for (int i = 2; i <= n; i++) {
			if (!composites[i]) {
				prime[k++] = i;
			}
			for (int j = 0; j < k && i * 1.0 * prime[j] <= n; j++) {
				composites[i * prime[j]] = true;
				if (i % prime[j] == 0) {
					break;
				}
			}
		}
		return Arrays.copyOf(prime, k);
	}

	public void run() {
		long time = System.currentTimeMillis();
		boolean oj = System.getProperty("ONLINE_JUDGE") != null;
		out = new PrintWriter(System.out);
		scn = new FastReader(oj);
		solve();
		out.flush();
		if (!oj) {
			System.out.println(Arrays.deepToString(new Object[] { System.currentTimeMillis() - time + " ms" }));
		}
	}

	public static void main(String[] args) {
		new Thread(null, new Main(), "Main", 1 << 26).start();
	}

	class FastReader {
		InputStream is;

		public FastReader(boolean onlineJudge) {
			is = onlineJudge ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		}

		byte[] inbuf = new byte[1024];
		public int lenbuf = 0, ptrbuf = 0;

		int readByte() {
			if (lenbuf == -1)
				throw new InputMismatchException();
			if (ptrbuf >= lenbuf) {
				ptrbuf = 0;
				try {
					lenbuf = is.read(inbuf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (lenbuf <= 0)
					return -1;
			}
			return inbuf[ptrbuf++];
		}

		boolean isSpaceChar(int c) {
			return !(c >= 33 && c <= 126);
		}

		int skip() {
			int b;
			while ((b = readByte()) != -1 && isSpaceChar(b))
				;
			return b;
		}

		double nextDouble() {
			return Double.parseDouble(next());
		}

		char nextChar() {
			return (char) skip();
		}

		String next() {
			int b = skip();
			StringBuilder sb = new StringBuilder();
			while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		String nextLine() {
			int b = skip();
			StringBuilder sb = new StringBuilder();
			while ((!isSpaceChar(b) || b == ' ')) { // when nextLine, (isSpaceChar(b) && b != ' ')
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		char[] next(int n) {
			char[] buf = new char[n];
			int b = skip(), p = 0;
			while (p < n && !(isSpaceChar(b))) {
				buf[p++] = (char) b;
				b = readByte();
			}
			return n == p ? buf : Arrays.copyOf(buf, p);
		}

		int nextInt() {
			int num = 0, b;
			boolean minus = false;
			while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
				;
			if (b == '-') {
				minus = true;
				b = readByte();
			}

			while (true) {
				if (b >= '0' && b <= '9') {
					num = num * 10 + (b - '0');
				} else {
					return minus ? -num : num;
				}
				b = readByte();
			}
		}

		long nextLong() {
			long num = 0;
			int b;
			boolean minus = false;
			while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
				;
			if (b == '-') {
				minus = true;
				b = readByte();
			}

			while (true) {
				if (b >= '0' && b <= '9') {
					num = num * 10 + (b - '0');
				} else {
					return minus ? -num : num;
				}
				b = readByte();
			}
		}

		char[][] nextMatrix(int n, int m) {
			char[][] map = new char[n][];
			for (int i = 0; i < n; i++)
				map[i] = next(m);
			return map;
		}

		int[] nextIntArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++)
				a[i] = nextInt();
			return a;
		}

		long[] nextLongArray(int n) {
			long[] a = new long[n];
			for (int i = 0; i < n; i++)
				a[i] = nextLong();
			return a;
		}

		int[][] next2DInt(int n, int m) {
			int[][] arr = new int[n][];
			for (int i = 0; i < n; i++) {
				arr[i] = nextIntArray(m);
			}
			return arr;
		}

		long[][] next2DLong(int n, int m) {
			long[][] arr = new long[n][];
			for (int i = 0; i < n; i++) {
				arr[i] = nextLongArray(m);
			}
			return arr;
		}

		int[] shuffle(int[] arr) {
			Random r = new Random();
			for (int i = 1, j; i < arr.length; i++) {
				j = r.nextInt(i);
				arr[i] = arr[i] ^ arr[j];
				arr[j] = arr[i] ^ arr[j];
				arr[i] = arr[i] ^ arr[j];
			}
			return arr;
		}

		int[] uniq(int[] arr) {
			Arrays.sort(arr);
			int[] rv = new int[arr.length];
			int pos = 0;
			rv[pos++] = arr[0];
			for (int i = 1; i < arr.length; i++) {
				if (arr[i] != arr[i - 1]) {
					rv[pos++] = arr[i];
				}
			}
			return Arrays.copyOf(rv, pos);
		}
	}
}