#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5e3 + 25;
vector <int> adj[MAXN];
pair <int, int> arr[MAXN];
int dist[MAXN][MAXN];
int main () {
ios::sync_with_stdio(0);
cin.tie(0);
int n, q;
cin >> n >> q;
for (int i = 1; i <= n; i++) {
int l, r;
cin >> l >> r;
arr[i] = {l, r};
}
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
if (i == j) continue;
if (arr[i].second >= arr[j].first && arr[i].second <= arr[j].second) {
adj[i].push_back(j);
}
}
}
for (int a = 1; a <= n; a++) {
for (int i = 1; i <= n; i++) {
dist[a][i] = 1e8;
}
dist[a][a] = 0;
queue <int> cur; cur.push(a);
while (!cur.empty()) {
auto k = cur.front();
cur.pop();
for (auto j : adj[k]) {
if (dist[a][j] > dist[a][k] + 1) {
dist[a][j] = dist[a][k] + 1;
cur.push(j);
}
}
}
}
while (q--) {
int a, b;
cin >> a >> b;
if (dist[a][b] > n) {
cout << "impossible\n";
} else {
cout << dist[a][b] << '\n';
}
}
}
