You are given n integer numbers a_1, a_2, ..., a_n. Consider graph on n nodes, in which nodes i, j (i≠ j) are connected if and only if, a_i AND a_j≠ 0, where AND denotes the [bitwise AND operation](https://en.wikipedia.org/wiki/Bitwise_operation#AND).

Find the length of the shortest cycle in this graph or determine that it doesn't have cycles at all.

Input

The first line contains one integer n (1 ≤ n ≤ 10^5) — number of numbers.

The second line contains n integer numbers a_1, a_2, ..., a_n (0 ≤ a_i ≤ 10^{18}).

Output

If the graph doesn't have any cycles, output -1. Else output the length of the shortest cycle.

Examples

Input


4
3 6 28 9


Output


4

Input


5
5 12 9 16 48


Output


3

Input


4
1 2 4 8


Output


-1

Note

In the first example, the shortest cycle is (9, 3, 6, 28).

In the second example, the shortest cycle is (5, 12, 9).

The graph has no cycles in the third example.
import java.io.BufferedOutputStream;
import java.io.Closeable;
import java.io.DataInputStream;
import java.io.Flushable;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.InputMismatchException;
import java.util.Objects;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
	static class TaskAdapter implements Runnable {
		@Override
		public void run() {
			long startTime = System.currentTimeMillis();
			InputStream inputStream = System.in;
			OutputStream outputStream = System.out;
			FastReader in = new FastReader(inputStream);
			Output out = new Output(outputStream);
			BShortestCycle solver = new BShortestCycle();
			solver.solve(1, in, out);
			out.close();
			System.err.println(System.currentTimeMillis()-startTime+"ms");
		}
	}

	public static void main(String[] args) throws Exception {
		Thread thread = new Thread(null, new TaskAdapter(), "", 1<<28);
		thread.start();
		thread.join();
	}

	static class BShortestCycle {
		private final int iinf = 1_000_000_000;
		ArrayList<Integer>[] graph;
		int n;

		public BShortestCycle() {
		}

		private int bfs(int u) {
			int ret = iinf;
			ArrayDeque<Pair<Integer, Integer>> q = new ArrayDeque<>(n);
			HashMap<Integer, Integer> dist = new HashMap<>(1<<8), par = new HashMap<>(1<<8);
			dist.put(u, 0);
			q.addLast(new Pair<>(u, 0));
			while(!q.isEmpty()) {
				var v = q.removeFirst();
				for(int x: graph[v.a]) {
					if(!dist.containsKey(x)) {
						dist.put(x, v.b+1);
						par.put(x, v.a);
						q.addLast(new Pair<>(x, v.b+1));
					}else if(par.getOrDefault(v.a, -1)!=x&&!par.getOrDefault(x, -1).equals(v.a)) {
						ret = Math.min(ret, dist.get(x)+dist.get(v.a)+1);
					}
				}
			}
			return ret;
		}

		public void solve(int kase, InputReader in, Output pw) {
			ArrayList<Integer>[] bit = new ArrayList[64];
			n = in.nextInt();
			for(int i = 0; i<64; i++) {
				bit[i] = new ArrayList<>();
			}
			for(int i = 0; i<n; i++) {
				long x = in.nextLong();
				for(int j = 0; j<64; j++) {
					if((x&1L<<j)>0) {
						bit[j].add(i);
					}
				}
			}
			for(int i = 0; i<64; i++) {
				if(bit[i].size()>2) {
					pw.println("3");
					return;
				}
			}
			graph = new ArrayList[n];
			for(int i = 0; i<n; i++) {
				graph[i] = new ArrayList<>();
			}
			for(int i = 0; i<64; i++) {
				if(bit[i].size()==2) {
					int a = bit[i].get(0), b = bit[i].get(1);
					graph[a].add(b);
					graph[b].add(a);
				}
			}
			Utilities.Debug.dbg(graph);
			int ans = iinf;
			for(int i = 0; i<n; i++) {
				if(!graph[i].isEmpty()) {
					ans = Math.min(ans, bfs(i));
				}
//			dbg(i, ans);
			}
			pw.println(ans==iinf ? -1 : ans);
		}

	}

	static class Pair<T1, T2> implements Comparable<Pair<T1, T2>> {
		public T1 a;
		public T2 b;

		public Pair(Pair<T1, T2> p) {
			this(p.a, p.b);
		}

		public Pair(T1 a, T2 b) {
			this.a = a;
			this.b = b;
		}

		public String toString() {
			return a+" "+b;
		}

		public int hashCode() {
			return Objects.hash(a, b);
		}

		public boolean equals(Object o) {
			if(o instanceof Pair) {
				Pair p = (Pair) o;
				return a.equals(p.a)&&b.equals(p.b);
			}
			return false;
		}

		public int compareTo(Pair<T1, T2> p) {
			int cmp = ((Comparable<T1>) a).compareTo(p.a);
			if(cmp==0) {
				return ((Comparable<T2>) b).compareTo(p.b);
			}
			return cmp;
		}

	}

	static class FastReader implements InputReader {
		final private int BUFFER_SIZE = 1<<16;
		private DataInputStream din;
		private byte[] buffer;
		private int bufferPointer;
		private int bytesRead;

		public FastReader(InputStream is) {
			din = new DataInputStream(is);
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public int nextInt() {
			int ret = 0;
			byte c = skipToDigit();
			boolean neg = (c=='-');
			if(neg) {
				c = read();
			}
			do {
				ret = ret*10+c-'0';
			} while((c = read())>='0'&&c<='9');
			if(neg) {
				return -ret;
			}
			return ret;
		}

		public long nextLong() {
			long ret = 0;
			byte c = skipToDigit();
			boolean neg = (c=='-');
			if(neg) {
				c = read();
			}
			do {
				ret = ret*10+c-'0';
			} while((c = read())>='0'&&c<='9');
			if(neg) {
				return -ret;
			}
			return ret;
		}

		private boolean isDigit(byte b) {
			return b>='0'&&b<='9';
		}

		private byte skipToDigit() {
			byte ret;
			while(!isDigit(ret = read())&&ret!='-') ;
			return ret;
		}

		private void fillBuffer() {
			try {
				bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
			}catch(IOException e) {
				e.printStackTrace();
				throw new InputMismatchException();
			}
			if(bytesRead==-1) {
				buffer[0] = -1;
			}
		}

		private byte read() {
			if(bytesRead==-1) {
				throw new InputMismatchException();
			}else if(bufferPointer==bytesRead) {
				fillBuffer();
			}
			return buffer[bufferPointer++];
		}

	}

	static class Output implements Closeable, Flushable {
		public StringBuilder sb;
		public OutputStream os;
		public int BUFFER_SIZE;
		public String lineSeparator;

		public Output(OutputStream os) {
			this(os, 1<<16);
		}

		public Output(OutputStream os, int bs) {
			BUFFER_SIZE = bs;
			sb = new StringBuilder(BUFFER_SIZE);
			this.os = new BufferedOutputStream(os, 1<<17);
			lineSeparator = System.lineSeparator();
		}

		public void println(int i) {
			println(String.valueOf(i));
		}

		public void println(String s) {
			sb.append(s);
			println();
			if(sb.length()>BUFFER_SIZE >> 1) {
				flushToBuffer();
			}
		}

		public void println() {
			sb.append(lineSeparator);
		}

		private void flushToBuffer() {
			try {
				os.write(sb.toString().getBytes());
			}catch(IOException e) {
				e.printStackTrace();
			}
			sb = new StringBuilder(BUFFER_SIZE);
		}

		public void flush() {
			try {
				flushToBuffer();
				os.flush();
			}catch(IOException e) {
				e.printStackTrace();
			}
		}

		public void close() {
			flush();
			try {
				os.close();
			}catch(IOException e) {
				e.printStackTrace();
			}
		}

	}

	static interface InputReader {
		int nextInt();

		long nextLong();

	}

	static class Utilities {
		public static class Debug {
			public static final boolean LOCAL = System.getProperty("ONLINE_JUDGE")==null;

			private static <T> String ts(T t) {
				if(t==null) {
					return "null";
				}
				try {
					return ts((Iterable) t);
				}catch(ClassCastException e) {
					if(t instanceof int[]) {
						String s = Arrays.toString((int[]) t);
						return "{"+s.substring(1, s.length()-1)+"}";
					}else if(t instanceof long[]) {
						String s = Arrays.toString((long[]) t);
						return "{"+s.substring(1, s.length()-1)+"}";
					}else if(t instanceof char[]) {
						String s = Arrays.toString((char[]) t);
						return "{"+s.substring(1, s.length()-1)+"}";
					}else if(t instanceof double[]) {
						String s = Arrays.toString((double[]) t);
						return "{"+s.substring(1, s.length()-1)+"}";
					}else if(t instanceof boolean[]) {
						String s = Arrays.toString((boolean[]) t);
						return "{"+s.substring(1, s.length()-1)+"}";
					}
					try {
						return ts((Object[]) t);
					}catch(ClassCastException e1) {
						return t.toString();
					}
				}
			}

			private static <T> String ts(T[] arr) {
				StringBuilder ret = new StringBuilder();
				ret.append("{");
				boolean first = true;
				for(T t: arr) {
					if(!first) {
						ret.append(", ");
					}
					first = false;
					ret.append(ts(t));
				}
				ret.append("}");
				return ret.toString();
			}

			private static <T> String ts(Iterable<T> iter) {
				StringBuilder ret = new StringBuilder();
				ret.append("{");
				boolean first = true;
				for(T t: iter) {
					if(!first) {
						ret.append(", ");
					}
					first = false;
					ret.append(ts(t));
				}
				ret.append("}");
				return ret.toString();
			}

			public static void dbg(Object... o) {
				if(LOCAL) {
					System.err.print("Line #"+Thread.currentThread().getStackTrace()[2].getLineNumber()+": [");
					for(int i = 0; i<o.length; i++) {
						if(i!=0) {
							System.err.print(", ");
						}
						System.err.print(ts(o[i]));
					}
					System.err.println("]");
				}
			}

		}

	}
}

