#include <bits/stdc++.h>
using namespace std;
template <typename A, typename B>
string to_string( pair<A, B> p ) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename T>
string to_string (T x) {
string S = "[";
bool first = true;
for (const auto v : x) {
if (!first) S += ", ";
S += to_string(v);
first = false;
}
S += "]";
return S;
}
string to_string( string s) {
return s;
}
void dbg_out () { cout << endl; }
template<typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
cout << to_string(H) << " ";
dbg_out(T...);
}
#ifdef TDEBUG
# define dbg(...) { cout << "(" << #__VA_ARGS__ << "): "; dbg_out(__VA_ARGS__); }
#else
# define dbg(...)
#endif
using Event = pair<int, int>;
using VEvent = vector<Event>;
using Time = pair<pair<int, int>, pair<int, bool>>;
using VTime = vector<Time>;
using idata = vector<int>;
using igrid = vector<idata>;
struct CNT {
set<pair<pair<int, int>, int>> m;
void insert (int index, int left, int right) {
while (m.size() != 0) {
auto it = m.end(); it --;
const auto data = *it;
if (left <= data.first.second && data.first.first <= right)
m.erase(data);
else break ;
}
if (m.size() != 0) {
auto it = m.end(); it --;
const auto data = *it;
if (right <= data.first.first && data.first.second <= left) return ;
}
m.insert({ {right, left}, index });
dbg(index, left, right, m);
}
int query (int start) {
dbg(start, m);
auto it =m.lower_bound({{ start, -1 }, -1});
if (it == m.end()) return -1;
return (*it).second;
}
};
const bool START = true;
const bool END = false;
VEvent events;
VTime timings;
idata parent;
igrid parent_2k;
const int MAXK = 20;
void initBLF () {
parent_2k.resize(parent.size(), idata(MAXK, -1));
for (int i = 0; i < parent.size(); i ++)
parent_2k[i][0] = parent[i];
for (int k = 0; k + 1 < MAXK; k ++) {
for (int i = 0; i < parent.size(); i ++) {
if (parent_2k[i][k] == -1) continue ;
parent_2k[i][k + 1] = parent_2k[parent_2k[i][k]][k];
}
}
}
pair<int, int> jump (int node, int finalEnd) {
int count = 0;
for (int k = MAXK - 1; k >= 0; k --) {
int pot = parent_2k[node][k];
if (pot == -1 || events[pot].first <= finalEnd) continue ;
node = pot;
count += 1 << k;
}
if (events[node].first <= finalEnd) return { node, 0 };
return { parent[node], count + 1 };
}
map<int, int> compress (idata coordinates) {
map<int, int> ans;
set<int> h;
for (int u : coordinates) h.insert(u);
int i = 0;
for (int u : h) ans.insert({ u, i ++ });
return ans;
}
int main () {
int N, Q;
cin >> N >> Q;
events.resize(N);
idata coords;
for (int i = 0; i < N; i ++) {
int a, b;
cin >> a >> b;
events[i] = { a, b };
coords.push_back(a);
coords.push_back(b);
}
map<int, int> mC = compress(coords);
for (int i = 0; i < N; i ++) {
//events[i].first = (*mC.find(events[i].first )).second;
//events[i].second = (*mC.find(events[i].second)).second;
timings.push_back({ { events[i].first, events[i].first }, { i, START } });
timings.push_back({ { events[i].second, events[i].first }, { i, END } });
}
sort(timings.begin(), timings.end());
CNT cnt;
parent.resize(N);
for (const auto &timing : timings) {
int id = timing.second.first;
bool F = timing.second.second;
if (F == START) {
} else {
parent[id] = cnt.query( events[id].first );
if (parent[id] != -1 && events[parent[id]].first >= events[id].first)
parent[id] = -1;
cnt.insert(id, events[id].first, events[id].second);
}
}
initBLF();
for (int q = 0; q < Q; q ++) {
int a, b;
cin >> a >> b;
a --;
b --;
if (a == b) {
cout << "0\n";
continue ;
}
if (events[a].second > events[b].second) {
cout << "impossible\n";
continue ;
}
pair<int, int> F = jump( b, events[a].second );
if (F.first == -1) cout << "impossible\n";
else cout << F.second + 1 << "\n";
}
}
