#include <bits/stdc++.h>
#define fst first
#define snd second
#define pb push_back
#define SZ(x) (int)x.size()
#define ALL(x) x.begin(),x.end()
#define forn(i,a,b) for(int i = a; i < b; i++)
#define mset(a,v) memset(a,v,sizeof(a))
#define FIN ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
using namespace std;
typedef int ll;
const int MAXN = 5000+4;
vector<ll> adj[MAXN];
ll n;
ll dijkstra(ll start, ll end){
vector<ll> cost(n,-1);
vector<bool> visit(n,false);
priority_queue<pair<ll,ll>> pq;
pq.push({0,start});
while(!pq.empty()){
ll nd = pq.top().snd;
ll cst = pq.top().fst*-1;
pq.pop();
if(visit[nd]) continue;
visit[nd]=true;
cost[nd]=cst;
for(auto i:adj[nd]){
pq.push({(cst+1)*-1,i});
}
}
return cost[end];
}
ll rcost[MAXN][MAXN];
void bfs(ll start){
//vector<ll> cost(n+1,-1);
//vector<bool> visit(n,false);
queue<pair<ll,ll>> cola;
cola.push({start,n});
//cost[n]=-1;
while(!cola.empty()){
ll nd = cola.front().fst;
ll p = cola.front().snd;
cola.pop();
if(rcost[start][nd]!=-1) continue;
rcost[start][nd]=rcost[start][p]+1;
//cout<<cost[nd]<<" "<<nd<<'\n';
for(auto i:adj[nd]) if(rcost[start][i]==-1){
cola.push({i,nd});
}
}
//forn(i,0,n) rcost[start][i]=cost[i];
//return cost[end];
}
int main(){ FIN;
mset(rcost,-1);
ll q; cin>>n>>q;
vector<pair<ll,ll>> r(n); forn(i,0,n) cin>>r[i].fst>>r[i].snd;
vector<pair<pair<ll,ll>,ll>> psr; // { { point, type } , ind }
forn(i,0,n){
psr.pb({{r[i].fst,0},i});
psr.pb({{r[i].snd,1},i});
}
sort(ALL(psr));
set<ll> s;
queue<pair<ll,ll>> cola;
forn(i,0,SZ(psr)){
while(!cola.empty()&&cola.front().fst<psr[i].fst.fst){
s.erase(s.find(cola.front().snd));
cola.pop();
}
if(psr[i].fst.snd==0){
s.insert(psr[i].snd);
}else{
//s.erase(s.find(psr[i].snd));
cola.push(pair<ll,ll>({psr[i].fst.fst,psr[i].snd}));
for(auto j:s) if(psr[i].snd!=j){
adj[psr[i].snd].pb(j);
//radj[j].pb(psr[i].snd);
}
}
}
forn(i,0,q){
ll s,e; cin>>s>>e; s--; e--;
if(rcost[s][s]==-1) bfs(s);
ll res = rcost[s][e];
if(res==-1) cout<<"impossible\n";
else cout<<res<<'\n';
}
return 0;
}
