#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::pair<time, int>> suff(n);
suff[n - 1] = {a[n - 1], n - 1};
for (int i = n - 2; i >= 0; --i) {
suff[i] = suff[i + 1];
if (a[i].e < suff[i].first.e) {
suff[i] = {a[i], i};
}
}
int tot_comps = 0, timer = 0;
std::vector<int> comp_num(n), start(n);
auto dfs = [&](auto &&self, int u) {
start[u] = timer++;
time t = {a[u].e, 0};
auto it = std::lower_bound(a.begin(), a.end(), t, comp);
int idx = suff[it - a.begin()].second;
if (it == a.end() or a[u].e > a[idx].e) {
comp_num[u] = tot_comps++;
return;
}
self(self, idx);
comp_num[u] = comp_num[idx];
};
dfs(dfs, 0);
while (q--) {
int beg, end;
std::cin >> 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';
}
}
}
