#include <bits/stdc++.h>
int main() {
int n, q;
std::cin >> n >> q;
struct time {
int s, e;
};
std::vector<time> a(n);
for (auto &[s, e] : a) {
std::cin >> s >> e;
}
auto comp = [](time a, time b) {
return a.s < b.s;
};
std::sort(a.begin(), a.end(), comp);
std::vector<std::vector<int>> pref(n);
pref[0] = {0};
for (int i = 1; i < n; ++i) {
pref[i] = pref[i - 1];
pref[i].push_back(i);
std::sort(pref[i].begin(), pref[i].end(), [&](int idx1, int idx2) {
return a[idx1].e > a[idx2].e;
});
if (pref[i].size() > 2) {
pref[i].pop_back();
}
}
int tot_comps = 0, timer = 0;
std::vector<int> comp_num(n), start(n);
std::vector<bool> vis(n);
auto dfs = [&](auto &&self, int u) {
if (vis[u]) {
return;
}
vis[u] = true;
start[u] = timer++;
time t = {a[u].e, 0};
auto it = std::upper_bound(a.begin(), a.end(), t, comp);
if (it == a.begin()) {
comp_num[u] = tot_comps++;
return;
}
--it;
if (pref[it - a.begin()].empty()) {
comp_num[u] = tot_comps++;
return;
}
int idx = pref[it - a.begin()][0];
if (u == idx) {
if (pref[it - a.begin()].size() == 1) {
comp_num[u] = tot_comps++;
return;
}
idx = pref[it - a.begin()][1];
}
if (a[u].e > a[idx].e) {
comp_num[u] = tot_comps++;
return;
}
self(self, idx);
comp_num[u] = comp_num[idx];
};
for (int i = 0; i < n; ++i) {
dfs(dfs, i);
}
while (q--) {
int beg, end;
std::cin >> beg >> end;
--beg, --end;
if (comp_num[beg] != comp_num[end] or start[beg] > start[end]) {
std::cout << "impossible\n";
} else {
std::cout << start[end] - start[beg] << '\n';
}
}
}
