/*
*
* author: AbdAlrhman_Sfar
*
**/
#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 5000 + 5;
const int LOG = 20;
vector<vector<int>> adj;
int dist[N][N];
void bfs(int&u) {
queue<int> q;
q.push(u); dist[u][u] = 0;
while (q.size()) {
int v = q.front();
q.pop();
for (auto& it : adj[v]) {
if (dist[u][it] == 6000) {
dist[u][it] = dist[u][v] + 1;
q.push(it);
}
}
}
}
signed main() {
ios::sync_with_stdio(0), cin.tie(0);
int n, q; cin >> n >> q;
for (auto& it : dist) {
for (auto& i : it)
i = 6000;
}
adj.resize(n);
vector<pair<int, int>> v(n);
int i, j;
for (i = 0; i < n; ++i) {
cin >> v[i].first >> v[i].second;
for (j = 0; j < i; ++j) {
if (v[i].first <= v[j].second && v[j].second <= v[i].second) adj[j].emplace_back(i);
if (v[j].first <= v[i].second && v[i].second <= v[j].second) adj[i].emplace_back(j);
}
}
for (i = 0; i < n; ++i) bfs(i);
while (q--) {
int u, v; cin >> u >> v; --u, --v;
if (dist[u][v] == 6000) cout << "impossible\n";
else cout << dist[u][v] << '\n';
}
}
