The clique problem is one of the most well-known NP-complete problems. Under some simplification it can be formulated as follows. Consider an undirected graph G. It is required to find a subset of vertices C of the maximum size such that any two of them are connected by an edge in graph G. Sounds simple, doesn't it? Nobody yet knows an algorithm that finds a solution to this problem in polynomial time of the size of the graph. However, as with many other NP-complete problems, the clique problem is easier if you consider a specific type of a graph.

Consider n distinct points on a line. Let the i-th point have the coordinate xi and weight wi. Let's form graph G, whose vertices are these points and edges connect exactly the pairs of points (i, j), such that the distance between them is not less than the sum of their weights, or more formally: |xi - xj| ≥ wi + wj.

Find the size of the maximum clique in such graph.

Input

The first line contains the integer n (1 ≤ n ≤ 200 000) — the number of points.

Each of the next n lines contains two numbers xi, wi (0 ≤ xi ≤ 109, 1 ≤ wi ≤ 109) — the coordinate and the weight of a point. All xi are different.

Output

Print a single number — the number of vertexes in the maximum clique of the given graph.

Examples

Input

4
2 3
3 1
6 1
0 2


Output

3

Note

If you happen to know how to solve this problem without using the specific properties of the graph formulated in the problem statement, then you are able to get a prize of one million dollars!

The picture for the sample test.

<image>
/*
 * Author Ayub Subhaniya
 * Institute DA-IICT
 */

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

public class Codeforces429C
{
	
	InputStream in;
	PrintWriter out;

	
	void solve() 
	{
		int n=ni();
		Pair p[]=new Pair[n];
		ArrayList<Integer> values=new ArrayList<>();
		HashMap<Integer,Integer> comp=new HashMap<>();
		for (int i=0;i<n;i++)
		{
			int x=ni();
			int w=ni();
			p[i]=new Pair(x,w);
			values.add(x-w);
			values.add(x+w);
		}
		Collections.sort(values);
		Arrays.sort(p);
		int idx=0;
		for (int i:values)
			if (!comp.containsKey(i))
				comp.put(i, idx++);
		int ans=0;
		SegmentTree st=new SegmentTree(idx);
		
		for (int i=0;i<n;i++)
		{
			int val=st.get(0, idx, 0, comp.get(p[i].s),1)+1;
			st.update(0, idx, comp.get(p[i].e), comp.get(p[i].e), val, 1);
			ans=Math.max(ans, val);
		}
		out.println(ans);
	}
	
	class Pair implements Comparable<Pair> 
	{
		int x;
		int y;
		int s,e;
		Pair(int a, int b) 
		{
			x = a;
			y = b;
			s=x-y;
			e=x+y;
		}

		@Override
		public boolean equals(Object o) 
		{
			Pair other = (Pair) o;
			return x == other.x && y == other.y;
		}

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

		@Override
		public int compareTo(Pair o) 
		{
			//if (s == o.s)
				return Integer.compare(s, o.s);
			//else
				//return Integer.compare(s, o.s);
		}

		@Override
		public int hashCode() 
		{
			return Objects.hash(x, y);
		}
	}
	
	class SegmentTree 
	{
        int st[];
 
        SegmentTree(int n)  
        {
            st = new int[4*n];
        }
        
        int getMid(int s, int e) 
        {
            return (s+e)>>1;
        }

        int merge(int a,int b)
        {
            return Math.max(a,b);
        }
        
        void update(int s, int e, int x, int y, int c, int si)
        {
            if(s == x && e == y)
            {
                st[si] = c;
            }
            else
            {
                int mid = getMid(s, e);
                if(y <= mid)    
                    update(s, mid, x, y, c, 2*si);
                else if(x > mid)
                    update(mid + 1, e, x ,y ,c ,2*si + 1);
                else
                {
                    update(s, mid, x, mid, c, 2*si);
                    update(mid + 1, e, mid + 1, y, c, 2*si + 1);
                }
                st[si] = merge(st[2*si],st[2*si+1]);
            }
        }

        int get(int s, int e, int x, int y, int si)
        {

            if(s == x && e == y)
            {
                return st[si];
            }
            int mid = getMid(s, e);
            if(y <= mid)
                return get(s, mid, x, y, 2*si);
            else if(x > mid)
                return get(mid + 1, e, x, y, 2*si + 1);
            return merge(get(s, mid, x, mid, 2*si), get(mid + 1, e, mid + 1, y, 2*si + 1));
        }
        
    }
	
	
	void run() throws Exception 
	{
		String INPUT = "C:/Users/ayubs/Desktop/input.txt";
		in = oj ? System.in : new FileInputStream(INPUT);
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		tr(System.currentTimeMillis() - s + "ms");
		
	}
	public static void main(String[] args) throws Exception 
	{
		new Codeforces429C().run();
	}
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte() 
	{
		if (lenbuf == -1)
			throw new InputMismatchException();
		if (ptrbuf >= lenbuf) 
		{
			ptrbuf = 0;
			try 
			{
				lenbuf = in.read(inbuf);
			}
			catch (IOException e) 
			{
				throw new InputMismatchException();
			}
			if (lenbuf <= 0)
				return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean inSpaceChar(int c) 
	{
		return !(c >= 33 && c <= 126);
	}
	
	private int skip() 
	{
		int b;
		while ((b = readByte()) != -1 && inSpaceChar(b))
			;
		return b;
	}
	
	private double nd() 
	{
		return Double.parseDouble(ns());
	}
	
	private char nc() 
	{
		return (char) skip();
	}
	
	private String ns() 
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while (!(inSpaceChar(b))) 
		{ // when nextLine, (inSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n) 
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while (p < n && !(inSpaceChar(b))) 
		{
			buf[p++] = (char) b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m) 
	{
		char[][] map = new char[n][];
		for (int i = 0; i < n; i++)
			map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n) 
	{
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = ni();
		return a;
	}
	
	private int ni() 
	{
		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();
		}
	}
	
	private long nl() 
	{
		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();
		}
	}
	
	private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
	
	private void tr(Object... o) 
	{
		if (!oj)
			System.out.println(Arrays.deepToString(o));
	}
	
}