Mary has just graduated from one well-known University and is now attending celebration party. Students like to dream of a beautiful life, so they used champagne glasses to construct a small pyramid. The height of the pyramid is n. The top level consists of only 1 glass, that stands on 2 glasses on the second level (counting from the top), then 3 glasses on the third level and so on.The bottom level consists of n glasses.

Vlad has seen in the movies many times how the champagne beautifully flows from top levels to bottom ones, filling all the glasses simultaneously. So he took a bottle and started to pour it in the glass located at the top of the pyramid.

Each second, Vlad pours to the top glass the amount of champagne equal to the size of exactly one glass. If the glass is already full, but there is some champagne flowing in it, then it pours over the edge of the glass and is equally distributed over two glasses standing under. If the overflowed glass is at the bottom level, then the champagne pours on the table. For the purpose of this problem we consider that champagne is distributed among pyramid glasses immediately. Vlad is interested in the number of completely full glasses if he stops pouring champagne in t seconds.

Pictures below illustrate the pyramid consisting of three levels.

<image> <image>

Input

The only line of the input contains two integers n and t (1 ≤ n ≤ 10, 0 ≤ t ≤ 10 000) — the height of the pyramid and the number of seconds Vlad will be pouring champagne from the bottle.

Output

Print the single integer — the number of completely full glasses after t seconds.

Examples

Input

3 5


Output

4


Input

4 8


Output

6

Note

In the first sample, the glasses full after 5 seconds are: the top glass, both glasses on the second level and the middle glass at the bottom level. Left and right glasses of the bottom level will be half-empty.


import java.awt.List;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.math.BigInteger;
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.Iterator;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.*;


 
 
public class cool {

	private static InputStream stream;
	private static PrintWriter pw;
	
	
	
//	static int a;
//	static int b;
//	static int f = 0;
	static int n;
	static int m;
//	static int[][] arr;
	//static char[][] arr;
	
	static int Arr[];
	static int tree[];
	
	static int time = 0;
	
	static int[][] dir = {{-1,0},{0,1},{1,0},{0,-1}};

	static int visited[];
	static int visited2[][];
	static Stack<Integer> stack;
	
//	static ArrayList<Integer> ans;

//	static int arr[][];
//	static int arr[];
	static char[][] arr;
	static char[][] ans;
//	static int[][] visited;
//  static int c;
//	static int d[];
//	static int arr[][];
	static ArrayList[] adj;
//	static ArrayList<Integer> ans;
//	static int f;
	static int parent[];
	static int color[];
//	static ArrayList<Integer> comp[];

	static int f = 0;
	static int k = 0;
	static int count = 0;
	static int ini[];
	
	static ArrayList<Node> list;
	static ArrayList<Integer> ind;

	
	
	public static void main(String[] args){
		//InputReader(System.in);
		pw = new PrintWriter(System.out);
		
		Scanner in = new Scanner(System.in);

		int n = in.nextInt();
		int t = in.nextInt();
		
		in.nextLine();
		
		double arr[][] = new double[15][15];
		arr[1][1] = t;
		
		int ans = 0;
		
		for(int i = 1;i<=n;i++){
			for(int j = 1;j<=i;j++){
				if(arr[i][j] >= 1){
					arr[i+1][j] += (arr[i][j] - 1)/2;
					arr[i+1][j+1] += (arr[i][j] - 1)/2;
					ans++;
				}
			}
		}
		pw.println(ans);
		
		pw.close();
	}
	
	
	public static void dfs(int i,int c){
		
		if(visited[i] == 1){
			return;
		}
		
		visited[i] = 1;
		
		for(int j = 0;j<adj[i].size();j++){
			
			if(color[(int)adj[i].get(j)] == c){
				dfs((int)adj[i].get(j),c);
			}else{
				count++;
			}
			
		}
		
	}
	
	
	public static long pow(long n,long p,long m){
        long  result = 1;
         if(p==0)
           return 1;
       if (p==1)
           return n;
       while(p!=0)
       {
           if(p%2==1)
               result *= n;
           if(result>=m)
           result%=m;
           p >>=1;
           n*=n;
           if(n>=m)
           n%=m;
       }
       return result;
       }
	

	
	public static int cs(ArrayList<Integer> arr, int low, int high, int x)
	{
	  int mid;    
	 
	  if(x <= arr.get(low))
	    return low; 
	 
	  if(x > arr.get(high))
	    return -1;  
	 
	 
	  mid = (low + high)/2; 
	 
	  if(arr.get(mid) == x)
	    return mid;
	    
	  else if(arr.get(mid) < x)
	  {
	    if(mid + 1 <= high && x <= arr.get(mid+1))
	      return mid + 1;
	    else
	      return cs(arr, mid+1, high, x);
	  }
	   
	  else
	  {
	    if(mid - 1 >= low && x > arr.get(mid-1))
	      return mid;
	    else    
	      return cs(arr, low, mid - 1, x);
	  }
	}
	
	
	public static int fs(ArrayList<Integer> arr, int low, int high, int x)
	{
	   
	    if (low > high)
	        return -1;
	 
	    if (x >= arr.get(high))
	        return high;
	 
	    // Find the middle point
	    int mid = (low+high)/2;
	 
	    // If middle point is floor.
	    if (arr.get(mid) == x)
	        return mid;
	 
	    // If x lies between mid-1 and mid
	    if (mid > 0 && arr.get(mid-1) <= x && x < arr.get(mid))
	        return mid-1;
	 
	    // If x is smaller than mid, floor must be in
	    // left half.
	    if (x < arr.get(mid))
	        return fs(arr, low, mid-1, x);
	 
	    // If mid-1 is not floor and x is greater than
	    // arr[mid],
	    return fs(arr, mid+1, high, x);
	}
	 

	public static long gcd(long x, long y) {
		if (x == 0)
			return y;
		else
			return gcd( y % x,x);
	}
	
//	public static void dfs(int a,int p){
//		System.out.println(a);
//		if(a > 30000){
//			return;
//		}
//		
//		if(visited[a] == 1){
//			return;
//		}
//		
//		visited[a] = 1;
//		
//		if(ini[a] != 0){
//			count+= ini[a];
//		}
//		
//		int l = a-p;
//		
//		if(visited[a+l-1] == 0){
//			dfs(a+l-1,a);
//		}else if(visited[a+l] == 0){
//			dfs(a+l,a);
//		}else if(visited[a+l+1] == 0){
//			dfs(a+l+1,a);
//		}
//		
//	}
//	
	
	
	
	
	
	public static int prev(int i,boolean[] arr){
		
		while(arr[i]){
			if(i == 0){
				if(arr[i]){
					return -1;
				}else{
					return 0;
				}
				
				
			}
			
			
			i--;
			
		}
		
		return i;
		
		
	}
	
	
	public static int next(int i,boolean[] arr){
		
		
		while(arr[i]){
			if(i == arr.length-1){
				if(arr[i]){
					return -1;
				}else{
					return 0;
				}
			}
			
			i++;
		}
		
		
		return i;
	}
	

	
	private static Map<String, Integer> sortByValue(Map<String, Integer> unsortMap) {

        // 1. Convert Map to List of Map
        LinkedList<Entry<String, Integer>> list =
                new LinkedList<Map.Entry<String, Integer>>(unsortMap.entrySet());

        // 2. Sort list with Collections.sort(), provide a custom Comparator
        //    Try switch the o1 o2 position for a different order
        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
            public int compare(Map.Entry<String, Integer> o1,
                               Map.Entry<String, Integer> o2) {
                return (o1.getValue()).compareTo(o2.getValue());
            }
        });

        // 3. Loop the sorted list and put it into a new insertion order Map LinkedHashMap
        Map<String, Integer> sortedMap = new LinkedHashMap<String, Integer>();
        for (Map.Entry<String, Integer> entry : list) {
            sortedMap.put(entry.getKey(), entry.getValue());
        }

        /*
        //classic iterator example
        for (Iterator<Map.Entry<String, Integer>> it = list.iterator(); it.hasNext(); ) {
            Map.Entry<String, Integer> entry = it.next();
            sortedMap.put(entry.getKey(), entry.getValue());
        }*/


        return sortedMap;
    }

	
	public static ArrayList<Integer> Range(int[] numbers, int target) {
	  

	    int low = 0, high = numbers.length - 1;
	    // get the start index of target number
	    int startIndex = -1;
	    while (low <= high) {
	        int mid = (high - low) / 2 + low;
	        if (numbers[mid] > target) {
	            high = mid - 1;
	        } else if (numbers[mid] == target) {
	            startIndex = mid;
	            high = mid - 1;
	        } else
	            low = mid + 1;
	    }

	    // get the end index of target number
	    int endIndex = -1;
	    low = 0;
	    high = numbers.length - 1;
	    while (low <= high) {
	        int mid = (high - low) / 2 + low;
	        if (numbers[mid] > target) {
	            high = mid - 1;
	        } else if (numbers[mid] == target) {
	            endIndex = mid;
	            low = mid + 1;
	        } else
	            low = mid + 1;
	    }

	    ArrayList<Integer> list = new ArrayList<Integer>();
	    int c = 0;
	    if (startIndex != -1 && endIndex != -1){
	        for(int i = startIndex;i<=endIndex;i++){
	        	list.add(i);
	        }
	    }
	    
	    
	    return list;
	    
	    
	}

	
	
	 private static int root(int Arr[],int i)
	    {
	        while(Arr[ i ] != i)           //chase parent of current element until it reaches root
	        {
	            Arr[ i ] = Arr[ Arr[ i ] ] ; 
	            i = Arr[ i ];
	        }
	        return i;
	    }
	 
	 private static void union(int Arr[],int size[],int A,int B)
	    {
	        int root_A = root(Arr,A);
	        int root_B = root(Arr,B);
	     
	       System.out.println(root_A + " " + root_B);
	        if(root_A != root_B){
	        	 if(size[root_A] < size[root_B ])
	 	        {
	        		 Arr[ root_A ] = Arr[root_B];
	        		 size[root_B] += size[root_A];	 	
	 	        }
	 	        else
	 	        {   	
	 	        	Arr[ root_B ] = Arr[root_A];
	 	        	size[root_A] += size[root_B];	 	   
	 	        }	
	        }
	    }
	 
	 private static boolean find(int A,int B)
	    {
	        if( root(Arr,A)==root(Arr,B) )       //if A and B have the same root, it means that they are connected.
	        return true;
	        else
	        return false;
	    }
	 
	
	


//	
//	public static void bfs(int i){
//		
//		Queue<Integer> q=new LinkedList<Integer>();
//    	q.add(i);
//    	
//    	visited[i] = 1;
//    	c++;
//    	nodes++;
//    	while(!q.isEmpty()){
//    		int top=q.poll();
//    		
//    		Iterator<Integer> it= arr[top].listIterator();
//    		while(it.hasNext()){
//    			int next =it.next();
//    			
//    			if(visited[next] == 0){
//    				nodes++;
//    				visited[next] = 1;
//    				q.add(next);
//    			}
//    		
//    		}
//    	}
//		
//	}
	
	
	
//	public static void dfs(int i){
//		
//		
//		if(visited[i] == 1){
//			return;
//		}
//		
//		visited[i] = 1;
//		con[c].add(i);
//		//System.out.print(i + " ");
//		for(int j = 0;j<arr[i].size();j++){
//			dfs(arr[i].get(j));
//		}
//		
//	}
//	
//	
//	public static void dfss(int i){
//		if(visited[i] == 1){
//			return;
//		}
//		
//		visited[i] = 1;
//		
//		for(int j = 0;j<arr[i].size();j++){
//			dfss(arr[i].get(j));
//		}
//	//	System.out.println(i);
//		stack.push(i);
//	}
//	
//	public static void reverse(){
//		ArrayList[] temp = new ArrayList[n];
//		
//		for(int i = 0;i<n;i++){
//			temp[i] = new ArrayList();
//		}
//		
//		for(int i = 0;i<n;i++){
//			for(int j = 0;j<arr[i].size();j++){
//				temp[arr[i].get(j)].add(i);
//			}
//		}
//		
//		arr = temp;
//		
//	}
//	
//	
	
	
	
	
	
	
	public static boolean isPrime(int n) {
		// Corner cases
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;
 
		// This is checked so that we can skip 
		// middle five numbers in below loop
		if (n % 2 == 0 || n % 3 == 0)
			return false;
 
		for (int i = 5; i * i <= n; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;
 
		return true;
	}
	
		 
	 // union code starts	
	
	
	 
	 // union code ends
	
	
	 
//	 // Segment tree code begins
//	 
//	 
//	 static void build(int node,int start,int end)
//	 {
//	 if(start==end)
//	 tree[node]=a[start];
//	 else
//	 {
//	 int mid=(start+end)/2;
//	 build(2*node,start,mid);
//	 build(2*node+1,mid+1,end);
//	 if(tree[2*node]<tree[2*node+1])
//	 tree[node]=tree[2*node];
//	 else
//	 tree[node]=tree[2*node+1];
//	 }
//	 }
//	 
//	 
//	 static void update(int node,int start,int end,int idx,int val)
//	 {
//	 if(start==end)
//	 {
//	 a[idx]=val;
//	 tree[node]=val;
//	 }
//	 else
//	 {
//	 int mid=(start+end)/2;
//	 if(idx>=start&&idx<=mid)
//	 update(2*node,start,mid,idx,val);
//	 else
//	 update(2*node+1,mid+1,end,idx,val);
//	 if(tree[2*node]<tree[2*node+1])
//	 tree[node]=tree[2*node];
//	 else
//	 tree[node]=tree[2*node+1];
//	 }
//	 }
//	 
//	 static int query(int node,int start,int end,int l,int r)
//	 {
//	 if(l>end||start>r)
//	 return 100005;
//	 if(l<=start&&r>=end)
//	 return tree[node];
//	 int p1,p2;
//	 int mid=(start+end)/2;
//	 p1=query(2*node,start,mid,l,r);
//	 p2=query(2*node+1,mid+1,end,l,r);
//	 if(p1<p2)
//	 return p1;
//	 else
//	 return p2;
//	 }
//	 
//	 
//	 
//}

}

class Field{
	
	long a;
	long b;
	
	Field(long a,long b){
		this.a = Math.min(a, b);
		this.b = Math.max(a, b);
	}
	
	boolean greator(Field f){
		return (this.a >= f.a && this.b >= f.b);
	}
	
}


class Node{
	int a;
	int b;
}

class point{
	int a;
	int b;
}


class MyComp2 implements Comparator<Node>{
    
	@Override
	public int compare(Node o1, Node o2) {
		
		if( o1.b > o2.b){
			return 1;
		}else if( o1.b < o2.b){
			return -1;
		}else{
			if(o1.a == o2.a){
				return 0;
			}else if(o1.a > o2.a){
				return 1;
			}else if(o1.a < o2.a){
				return -1;
			}
		}
		
		return 0;
	}
}


class Card implements Comparable<Card>
{
	int a,b;
	public Card(int w,int h)
	{
		this.a=w;
		this.b=h;
		
	}
	public int compareTo(Card that)
	{
		return this.a-that.a;
	}
}
