#include <bits/stdc++.h>
using namespace std;
const int Log = 18;
const int N = 5003;
int dis[N][N];
int l[N], r[N];
vector<int> g[N];
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, q;
cin >> n >> q;
for (int i = 1; i <= n; ++i) {
cin >> l[i] >> r[i];
}
auto intersect = [&](int x, int i, int j) {
return x >= i && x <= j;
};
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
if (intersect(r[i], l[j], r[j])) {
g[i].push_back(j);
}
}
}
memset(dis, -1, sizeof dis);
auto Bfs = [&](int src) {
queue<int> que;
que.push(src);
dis[src][src] = 0;
while (!que.empty()) {
int v = que.front();
que.pop();
for (int u : g[v]) {
if (dis[src][u] == -1) {
dis[src][u] = dis[src][v] + 1;
que.push(u);
}
}
}
};
for (int i = 1; i <= n; ++i) {
Bfs(i);
// cout << "v : " << i << '\n';
// for (int j = 1; j <= n; ++j) {
// cout << dis[i][j] << ' ';
// }
// cout << '\n';
}
while (q--) {
int u, v;
cin >> u >> v;
if (dis[u][v] == -1) {
cout << "impossible" << '\n';
} else {
cout << dis[u][v] << '\n';
}
}
return 0;
}
