#include <bits/stdc++.h>
#define boost ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
const int inf=1e9;
const int N=1e5+5;
const int N1=1e5+5;
const int N2=5e6+6;
const int mod=1e9+7;
const int k1=447;
struct edge{
int d,in;
};
struct edge1{
int l,r;
};
vector<pair<int,int> >v1;
vector<int>v[N];
int dp[5005][5005];
signed main(){
boost;
int n,q;
cin>>n>>q;
for(int i=1;i<=n;i++){
int l,r;
cin>>l>>r;
v1.push_back({l,r});
}
for(int i=0;i<v1.size();i++){
for(int j=0;j<v1.size();j++){
if(j==i){
continue;
}
if(v1[i].second>v1[j].second||v1[i].second<v1[j].first){
continue;
}
v[i+1].push_back(j+1);
}
}
for(int i=1;i<=n;i++){
queue<int>q;
q.push(i);
dp[i][i]=1;
while(q.size()>0){
int x=q.front();
q.pop();
for(int j=0;j<v[x].size();j++){
if(dp[i][v[x][j]]==0){
dp[i][v[x][j]]=dp[i][x]+1;
q.push(v[x][j]);
}
}
}
}
for(int i=1;i<=q;i++){
int a,b;
cin>>a>>b;
if(dp[a][b]==0){
cout<<"impossible\n";
}else{
cout<<dp[a][b]-1<<"\n";
}
}
}
