#include <iostream>
#include <sstream>
#include <string>
#include<vector>
#include <algorithm>
#include<math.h>
using namespace std;
#define MAXN 10000
int A[MAXN];
int N;
int h(0);
int i, L1;
int k(0);
vector<int> v;
struct a
{
	int b;
	int e; 
	int l;
}c[500];
void BinarySearch(int x)
{
  int p, q,  L;
  for(int m=0;m<10001;m++)
  { 
	  N=m;

  q = N-1; 
  p = 0;   
  L = 0;   
  while (p <= q) {
    i = (p + q) / 2;
    ++L;
    if ((A[i] == x)&&(L==L1 ))
	{  
        v.push_back(m);
  	if((m)!=h+1 )
	{	k++;
 
	}
	  h=m;
    }
    if (x < A[i])
      q = i - 1;
    else
      p = i + 1;
  }
  }
  return ;
}
void main()
{  
int i;
int k2(0);
	for(i=0;i<10001;i++)
		A[i]=i;
cin>>i>>L1;
BinarySearch(i);

vector<int> v1;
cout<<k<<endl;
//sort(v.begin(),v.end());
if(v.size()==0)
;
else
{
for(i=0;i<v.size()-1;i++)
{
	v1.push_back(v.at(i));
if((v.at(i)+1)!=v.at(i+1))
{
    k2++;
	c[k2].b=v1.front();
	c[k2].e=v1.back();
   c[k2].l=v1.size();
 //cout<<v1.front()<<" "<<v1.back()<<endl;
      v1.clear();
}
}
v1.push_back(v.back());
k2++;
c[k2].b=v1.front();
	c[k2].e=v1.back();
    c[k2].l=v1.size();
for( i=1;i<=k2;i++)
for(int j=i+1;j<=k2;j++)
if(c[i].l>c[j].l )
{
swap(c[i].l,c[j].l);
swap(c[i].b,c[j].b);
swap(c[i].e,c[j].e);
}
for( i=1;i<=k2;i++)
{

cout<<c[i].b<<" "<<c[i].e<<endl;
}
}


}