There are n psychos standing in a line. Each psycho is assigned a unique integer from 1 to n. At each step every psycho who has an id greater than the psycho to his right (if exists) kills his right neighbor in the line. Note that a psycho might kill and get killed at the same step. 

You're given the initial arrangement of the psychos in the line. Calculate how many steps are needed to the moment of time such, that nobody kills his neighbor after that moment. Look notes to understand the statement more precise.

Input

The first line of input contains integer n denoting the number of psychos, (1 ≤ n ≤ 105). In the second line there will be a list of n space separated distinct integers each in range 1 to n, inclusive — ids of the psychos in the line from left to right.

Output

Print the number of steps, so that the line remains the same afterward.

Examples

Input

10
10 9 7 8 6 5 3 4 2 1


Output

2


Input

6
1 2 3 4 5 6


Output

0

Note

In the first sample line of the psychos transforms as follows: [10 9 7 8 6 5 3 4 2 1]  →  [10 8 4] →  [10]. So, there are two steps.
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.TreeSet;
import java.lang.Long;

public class Test {
	static long mod = 1000000007;
	static int[] dp;

	static int contains;

	public static void main(String[] args) throws FileNotFoundException {
		PrintWriter out = new PrintWriter(System.out);
		Scanner in = new Scanner();
		int n = in.nextInt();
		int[]data = new int[n];
		LinkedList<Integer> list = new LinkedList();
		for(int i = 0; i < n; i++){
			int v = in.nextInt();
			list.add(v);
		}
		int result = 0;
		while(true){
			int pre = list.size();
			LinkedList<Integer> nxt = new LinkedList();
			int last = -1;
			while(!list.isEmpty()){
				int v = list.removeLast();
				if(v < last){
					nxt.addFirst(v);
				}
				last = v;
			}
			nxt.addFirst(last);
			if(nxt.size() == pre){
				break;
			}
			list = nxt;
			//System.out.println(list);
			result++;
		}
		out.println(result);
	
		out.close();
	}

	static class Edge implements Comparable<Edge> {
		int x, y, w;

		public Edge(int x, int y, int w) {
			super();
			this.x = x;
			this.y = y;
			this.w = w;
		}

		public int compareTo(Edge o) {
			if (w != o.w)
				return w - o.w;
			return x - o.x;
		}

	}

	static int crossProduct(Point a, Point b) {
		return a.x * b.y + a.y * b.x;
	}

	static long squareDist(Point a) {
		long x = a.x;
		long y = a.y;
		return x * x + y * y;
	}

	static Point minus(Point a, Point b) {
		return new Point(a.x - b.x, a.y - b.y);
	}

	public static boolean nextPer(int[] data) {
		int i = data.length - 1;
		while (i > 0 && data[i] < data[i - 1]) {
			i--;
		}
		if (i == 0) {
			return false;
		}
		int j = data.length - 1;
		while (data[j] < data[i - 1]) {
			j--;
		}
		int temp = data[i - 1];
		data[i - 1] = data[j];
		data[j] = temp;
		Arrays.sort(data, i, data.length);
		return true;
	}

	static class Point {
		int x, y;

		public Point(int x, int y) {
			super();
			this.x = x;
			this.y = y;
		}

		public String toString() {
			return "{" + x + " " + y + "}";
		}

	}

	static class Entry implements Comparable<Entry> {
		int x, cost;

		public Entry(int x, int cost) {
			super();
			this.x = x;
			this.cost = cost;
		}

		public int compareTo(Entry o) {
			// TODO Auto-generated method stub
			if (cost > o.cost) {
				return 1;
			} else if (cost == o.cost) {
				return -1;
			}

			return 0;
		}
	}

	static int gcd(int a, int b) {
		if (b == 0) {
			return a;
		}
		return gcd(b, a % b);
	}

	static class Scanner {

		BufferedReader br;
		StringTokenizer st;

		public Scanner() throws FileNotFoundException {
			// System.setOut(new PrintStream(new
			// BufferedOutputStream(System.out), true));
			br = new BufferedReader(new InputStreamReader(System.in));
			// br = new BufferedReader(new InputStreamReader(new
			// FileInputStream(new File("B-large.in"))));
		}

		public String next() {

			while (st == null || !st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (Exception e) {
					throw new RuntimeException();
				}
			}
			return st.nextToken();
		}

		public long nextLong() {
			return Long.parseLong(next());
		}

		public int nextInt() {
			return Integer.parseInt(next());
		}

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

		public String nextLine() {
			st = null;
			try {
				return br.readLine();
			} catch (Exception e) {
				throw new RuntimeException();
			}
		}

		public boolean endLine() {
			try {
				String next = br.readLine();
				while (next != null && next.trim().isEmpty()) {
					next = br.readLine();
				}
				if (next == null) {
					return true;
				}
				st = new StringTokenizer(next);
				return st.hasMoreTokens();
			} catch (Exception e) {
				throw new RuntimeException();
			}
		}
	}
}