#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 FIN ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
using namespace std;
typedef long long ll;
const int MAXN = 100000+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];
}
int main(){ FIN;
ll q; cin>>n>>q;
vector<pair<ll,ll>> r(n); forn(i,0,n) cin>>r[i].fst>>r[i].snd;
forn(i,0,n){
forn(j,0,n){
if(i==j) continue;
if(r[i].snd>=r[j].fst&&r[i].snd<=r[j].snd){
adj[i].pb(j);
}
}
}
forn(i,0,q){
ll s,e; cin>>s>>e; s--; e--;
ll res = dijkstra(s,e);
if(res==-1) cout<<"impossible\n";
else cout<<res<<'\n';
}
return 0;
}
