#include <bits/stdc++.h>
#define MAX 10005
int N,Q;
typedef std::pair<int,int> pii;
std::vector<pii> eventos;
std::vector<int> add[MAX];
std::vector<int> rem[MAX];
int catalogo_avanco[MAX];
bool moscando[MAX];
int visitado[MAX];
void explora(int x){
memset(&catalogo_avanco,0,sizeof(catalogo_avanco));
memset(&visitado,0,sizeof(visitado));
memset(&moscando,0,sizeof(moscando));
catalogo_avanco[eventos[x].second]=1;
for(int i=0;i!=MAX;++i){
for(auto&x:add[i]){
moscando[x]=true;
}
int d = catalogo_avanco[i];
if(d){
for(int i=0;i!=N;++i){
auto& x = moscando[i];
if(!x)continue;
if(d){
if(!visitado[i])
visitado[i]=d+1;
else visitado[i]=std::min(visitado[i],d+1);
}
// std::cout<<"Visita "<<x.first<<" "<<d<<" "<<i<<"\n";
if(!catalogo_avanco[eventos[i].second])catalogo_avanco[eventos[i].second]=d+1;
else
catalogo_avanco[eventos[i].second]=std::min((int)catalogo_avanco[eventos[i].second],d+1);
}
}
for(auto&x:rem[i]){
moscando[x]=false;
}
}
}
typedef std::pair<int,int*> pipo;
int main()
{
std::ios::sync_with_stdio(false);
std::cin.tie(0);
std::cout.tie(0);
std::cin>>N>>Q;
for(int i=0;i!=N;++i){
int a,b;
std::cin>>a>>b;
eventos.push_back({a,b});
}
{
std::vector<pipo> comprime;
for(auto&x:eventos){
comprime.push_back({x.first,&x.first});
comprime.push_back({x.second,&x.second});
}
std::sort(comprime.begin(),comprime.end());
int last=-1,cord=1;
for(auto&x:comprime){
if(x.first!=last){
last=x.first;
++cord;
}
*x.second=cord;
}
}
for(int i=0;i!=N;++i){
add[eventos[i].first].push_back(i);
rem[eventos[i].second].push_back(i);
}
for(int i=0;i!=Q;++i){
int s,e;
std::cin>>s>>e;--s;--e;
if(s==e){
std::cout<<"0\n";
continue;
}
explora(s);
if(visitado[e]){
std::cout<<visitado[e]-1<<"\n";
}else std::cout<<"impossible\n";
}
}
