#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10, LG = 18;
int n, que, par[N][LG], a[N][2], dist[5005][5005], edge[5005][5005];
vector<pair<pair<int, int>, int>> vec;
vector<int> g[N];
int main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> que;
for (int i = 0; i < n; i ++){
int s, e;
cin >> s >> e;
a[i][0] = s, a[i][1] = e;
// vec.push_back({{s, 0}, i});
// vec.push_back({{e, 1}, i});
}
// sort(vec.begin(), vec.end());
for (int i = 0; i < n; i ++){
for (int j = 0; j < n; j ++){
if (i == j) continue;
if (a[i][0] <= a[j][1] and a[j][1] <= a[i][1])
edge[j][i] = 1;
}
}
queue<int> q;
for (int s = 0; s < n; s ++){
dist[s][s] = 1;
q.push(s);
while (!q.empty()){
int v = q.front();
q.pop();
for (int u = 0; u < n; u ++){
if (!edge[v][u]) continue;
if (dist[s][u] == 0){
dist[s][u] = dist[s][v] + 1;
q.push(u);
}
}
}
}
for (int id = 0; id < que; id ++){
int l, r;
cin >> l >> r;
l--; r--;
if (dist[l][r] == 0)
cout << "impossible\n";
else
cout << dist[l][r] - 1 << '\n';
}
return 0;
}
