#include "bits/stdc++.h"
using namespace std;
#ifdef duc_debug
#include "bits/debug.h"
#else
#define debug(...)
#endif
const int maxn = 3e5 + 5;
const int LG = 19;
int n, q;
int sl[maxn], sr[maxn];
int ord[maxn];
vector<int> ev[maxn];
int up[maxn][LG + 1];
void solve() {
cin >> n >> q;
vector<int> cprs;
for (int i = 1; i <= n; ++i) {
cin >> sl[i] >> sr[i];
cprs.push_back(sl[i]);
cprs.push_back(sr[i]);
cprs.push_back(sl[i] - 1);
}
sort(cprs.begin(), cprs.end());
cprs.erase(unique(cprs.begin(), cprs.end()), cprs.end());
for (int i = 1; i <= n; ++i) {
int d = lower_bound(cprs.begin(), cprs.end(), sl[i] - 1) - cprs.begin() + 1;
sl[i] = lower_bound(cprs.begin(), cprs.end(), sl[i]) - cprs.begin() + 1;
sr[i] = lower_bound(cprs.begin(), cprs.end(), sr[i]) - cprs.begin() + 1;
ev[sr[i]].push_back(i);
if (d > 1) ev[d - 1].push_back(-i);
}
set<pair<int, int>> s;
for (int i = (int)cprs.size(); i; --i) {
if (ev[i].empty()) continue;
sort(ev[i].begin(), ev[i].end());
for (auto j : ev[i]) {
if (j < 0) {
j = -j;
s.erase(s.find(make_pair(sr[j], j)));
} else {
s.insert(make_pair(sr[j], j));
}
}
for (auto j : ev[i]) {
if (j > 0) {
if (!s.empty()) {
auto it = s.rbegin();
if (j != it->second) {
up[j][0] = it->second;
}
}
}
}
}
for (int j = 1; j <= LG; ++j) {
for (int i = 1; i <= n; ++i) {
up[i][j] = up[up[i][j - 1]][j - 1];
}
}
while (q--) {
int s, e; cin >> s >> e;
if (s == e) {
cout << 0 << '\n';
continue;
}
if (sr[e] < sr[s]) {
cout << "impossible\n";
continue;
}
int ans = 0;
int cur = s;
for (int i = LG; i >= 0; --i) {
if (up[cur][i] and sr[up[cur][i]] < sr[e]) {
ans ^= (1 << i);
cur = up[cur][i];
}
}
if (sl[e] <= sr[cur]) cout << ans + 1 << '\n';
else {
// debug(cur, up[cur][0]);
cur = up[cur][0];
if (!cur || sr[cur] > sr[e]) cout << "impossible\n";
else cout << ans + 2 << '\n';
}
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
