#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
const int M = 5000;
int dis[M][M],n;
vector<int> nei[M];
void bfs(int u)
{
for (int i=0;i<n;i++) dis[u][i]=M;
dis[u][u]=0;
queue<int> q;
q.push(u);
while (!q.empty())
{
int x=q.front();q.pop();
if (x<u)
{
for (int i=0;i<n;i++)
if (dis[u][i]>dis[u][x]+dis[x][i])
dis[u][i]=dis[u][x]+dis[x][i],q.push(i);
}
else
for (int i:nei[x])
if (dis[u][i]>dis[u][x]+1)
dis[u][i]=dis[u][x]+1,q.push(i);
}
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(NULL), cout.tie(NULL);
int 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++)
for (int j=0;j<n;j++)
if (i!=j && s[j]<=e[i] && e[i]<=e[j])
nei[i].push_back(j);
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 if(n<=5000)
{
int s[n],e[n];
for (int i=0;i<n;i++)
cin>>s[i]>>e[i];
for (int i=0;i<n;i++)
for (int j=0;j<n;j++)
if (i!=j && s[j]<=e[i] && e[i]<=e[j])
nei[i].push_back(j);
for (int i=0;i<n;i++)
bfs(i);
while (q--)
{
int s1,e1;
cin>>s1>>e1;s1--,e1--;
if (dis[s1][e1]==M)
cout<<"impossible"<<endl;
else
cout<<dis[s1][e1]<<endl;
}
}
else
{
}
return 0;
}
