#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define all(v) v.begin(), v.end()
const int M = 5000;
int dis[M][M],nx[M][M];
void bfs(int u)
{
for (int i=0;i<M;i++) dis[u][i]=M;
dis[u][u]=0;
queue<int> q;
q.push(u);
while (!q.empty())
{
int x=q.front();q.pop();
int cur=x;
while (nx[x][cur]<M)
{
int i=nx[x][cur];
if (dis[u][i]>dis[u][x]+1)
dis[u][i]=dis[u][x]+1,q.push(i);
cur=i;
}
}
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(NULL), cout.tie(NULL);
int n,q;
cin>>n>>q;
if (n<=1000 && q<=100)
{
int s[n],e[n];
for (int i=0;i<n;i++)
cin>>s[i]>>e[i];
for (int i=0;i<n;i++)
{
int p=i;
for (int j=0;j<n;j++)
if (i!=j && s[j]<=e[i] && e[i]<=e[j])
nx[i][p]=j,p=j;
nx[i][p]=M;
}
while (q--)
{
int s1,e1;
cin>>s1>>e1;s1--,e1--;
bfs(s1);
if (dis[s1][e1]==M)
cout<<"impossible"<<endl;
else
cout<<dis[s1][e1]<<endl;
}
}
else
{
int s[n],e[n],col[n],id[n]={};
vector<vector<int>> v;
for (int i=0;i<n;i++)
{
cin>>s[i]>>e[i];
col[i]=i;
v.push_back({s[i],i,1});
v.push_back({e[i],i,0});
}
set<int> se;
sort(all(v));
for (auto v1:v)
{
if (v1[2]) se.insert(v1[1]);
else
{
se.erase(v1[1]);
if (!se.empty())
col[*se.begin()]=col[v1[1]],id[*se.begin()]=id[v1[1]]+1;
}
}
while (q--)
{
int s1,e1;
cin>>s1>>e1;
if (col[s1]==col[e1] && id[e1]>=id[s1])
cout<<id[e1]-id[s1]<<endl;
else
cout<<"impossible"<<endl;
}
}
return 0;
}
