#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vi vector<ll>
#define pp pair<ll, ll>
#define vp vector<pp>
#define vpp vector<pair<ll, pp>>
#define inf 1000000000
int main(){
ios_base::sync_with_stdio(false);
cin.tie();
ll n, q;
cin >> n >> q;
vp seg(n);
vpp points;
for(int i = 0; i < n; i++){
cin >> seg[i].first >> seg[i].second;
points.push_back({seg[i].first, {0, i}});
points.push_back({seg[i].second, {1, i}});
}
sort(points.begin(), points.end());
//sort(seg.begin(), seg.end());
set<pp> sp;
vector<vector<pair<ll, pp>>> queries(n); //kam, ans, ktera
for(int i = 0; i < q; i++){
ll ans = 0;
ll start, end;
cin >> start >> end;
start--; end--;
queries[start].push_back({end, {0, i}});
}
vp ans;
sp.clear();
for(int i = 0; i < points.size(); i++){
if(points[i].second.first == 0){
ll aktseg = points[i].second.second;
sp.insert({seg[aktseg].second, aktseg});
}else{
ll aktseg = points[i].second.second;
for(int j = 0; j < queries[aktseg].size(); j++){
pair<ll, pp> query = queries[aktseg][j];
if(query.first == aktseg){
ans.push_back({query.second.second, query.second.first});
continue;
}
ll to = seg[query.first].second;
auto au = sp.lower_bound({to, inf});
if(au == sp.begin() || sp.size() == 0){
ans.push_back({query.second.second, inf});
continue;
}
au--;
pp nxt = *au;
if(nxt.second == aktseg){
ans.push_back({query.second.second, inf});
continue;
}
queries[nxt.second].push_back({query.first, {query.second.first + 1, query.second.second}});
}
sp.erase({seg[aktseg].second, aktseg});
}
}
vi ANS(q);
for(int i = 0; i < ans.size(); i++){
ANS[ans[i].first] = ans[i].second;
}
for(int i = 0; i < ANS.size(); i++){
if(ANS[i] >= inf){
cout << "impossible" << '\n';
}else{
cout << ANS[i] << '\n';
}
}
}
