#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <math.h>
#include <string>
#include <algorithm>
#include <random>
#include <iomanip>
#include <utility>
#include <cstring>
//#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll N=1e3+9,M=1e18+9,mod=1e9+7;
//cout<<fixed<<setprecision(6)<<
ll s[N],e[N],n,q,i,j,k,ans;
bool vis[N];
vector<ll>v[N];
void dfs(ll node,ll num){
if(node==j){
k=1,ans=min(ans,num);
return;
}
if(vis[node])return;
++num,vis[node]=1;
for(auto p:v[node])dfs(p,num);
vis[node]=0;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n>>q;
for(i=1;i<=n;++i)cin>>s[i]>>e[i];
for(ll i=1;i<=n;++i){
for(ll j=1;j<=n;++j){
if(s[j]<=e[i] && e[i]<=e[j])
v[i].push_back(j);
}
}
while(q--){
cin>>i>>j;
k=0,ans=M;
dfs(i,0);
if(k)cout<<ans<<'\n';
else cout<<"impossible\n";
}
}
