#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e3 + 10;
int ls[MAXN], rs[MAXN], dist[MAXN];
vector<int> graph[MAXN];
bool marc[MAXN];
void bfs(int u, int n) {
for (int i = 0; i < n; ++i) {
marc[i] = false;
dist[i] = 0;
}
queue<int> q;
q.push(u);
marc[u] = true;
while (!q.empty()) {
int u = q.front(); q.pop();
for (int v: graph[u])
if (!marc[v]) {
marc[v] = true;
dist[v] = dist[u] + 1;
q.push(v);
}
}
}
int main() {
int n, q;
cin >> n >> q;
for (int i = 0; i < n; ++i)
cin >> ls[i] >> rs[i];
for (int i = 0; i < n; ++i)
for (int j = 0; j < n; ++j)
if (i != j && ls[i] <= rs[j] && rs[j] <= rs[i])
graph[j].push_back(i);
for (int i = 0; i < q; ++i) {
int a, b;
cin >> a >> b;
--a; --b;
bfs(a, n);
if (!marc[b]) cout << "impossible\n";
else cout << dist[b] << "\n";
}
}
