#include "bits/stdc++.h"
using namespace std;
const int N = 5000;
int dist[N][N];
int l[N], r[N];
void go(set<pair<int, int>> s, int start) {
queue<int> q;
q.push(start);
dist[start][start] = 0;
s.erase({r[start], start});
while(!q.empty()) {
int u = q.front();
q.pop();
while(!s.empty()) {
auto it = s.upper_bound({l[u], -1});
if(it == s.end()) break;
if(it->first > r[u]) break;
dist[start][it->second] = dist[start][u] + 1;
q.push(it->second);
s.erase(it);
}
}
}
int main() {
int n, q; cin >> n >> q;
for(int i = 0; i < n; ++i) cin >> l[i] >> r[i];
set<pair<int, int>> s;
for(int i = 0; i < n; ++i) s.insert({r[i], i});
for(int i = 0; i < N; ++i) for(int j = 0; j < N; ++j) dist[i][j] = -1;
for(int i = 0; i < n; ++i) go(s, i);
while(q--) {
int a, b; cin >> a >> b; --a, --b;
if(dist[b][a] == -1) cout << "impossible\n";
else cout << dist[b][a] << "\n";
}
}
