import java.io.IOException;
import java.util.NoSuchElementException;


public class Main{

	public static void main(String args[])throws Exception{
		
		FastScanner sc = new FastScanner();
		int n = sc.nextInt();
		int[][] t = new int[n+1][n+1];
		for(int i = 1;i<=n;i++){
			String S = sc.next();
			for(int j=0;j<n/4;j++){
				int p = 0;
				char c = S.charAt(j);
				if('0'<=c&&c<='9'){
					p = c - '0';
				}else{
					p = c - 'A' + 10;
				}
				for(int k=4;k>0;k--){
					if(p%2==1){
						t[i][4*j+k] = 1;
					}
					p /= 2;
				}
			}
		}
	
		for(int i=1;i<=n;i++){
			for(int j=1;j<=n;j++){
				t[i][j] += t[i-1][j] + t[i][j-1] - t[i-1][j-1];
			}
		}

		for(int i=n;i>0;i--){
			if(n%i==0){
				int b = 0;
				for(int j=1;j<=n/i;j++){
					for(int k=1;k<=n/i;k++){
						if(t[j*i][k*i]%(i*i)!=0){
							b = 1;
						}
					}
				}
				if(b==0){
					System.out.println(i);
					return;
				}
			}
		}
	}
	
	
}







class FastScanner {
    private final java.io.InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    private void skipUnprintable() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;}
    public boolean hasNext() { skipUnprintable(); return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return (minus ? -n : n);
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return (int) (minus ? -n : n);
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
}
