#include <bits/stdc++.h>
#define F first
#define S second
using namespace std;
const int N = 5000 + 10;
int Dist[N][N], n, l[N], r[N];
vector<int> g[N];
void Bfs(int s) {
for(int i = 1; i <= n; i++) Dist[s][i] = n + 1;
queue<int> q;
Dist[s][s] = 0;
q.push(s);
while(!q.empty()) {
int u = q.front();
q.pop();
for(int j : g[u]) {
if(Dist[s][j] > Dist[s][u] + 1) {
Dist[s][j] = Dist[s][u] + 1;
q.push(j);
}
}
}
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int q;
cin >> n >> q;
for(int i = 1; i <= n; i++) cin >> l[i] >> r[i];
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= n; j++) {
if(i != j && l[j] <= r[i] && r[j] >= r[i]) {
//cout << i << " -> " << j << endl;
g[i].push_back(j);
}
}
}
for(int i = 1; i <= n; i++) Bfs(i);
while(q--) {
int l, r;
cin >> l >> r;
if(Dist[l][r] == n + 1) {
cout << "impossible\n";
} else {
cout << Dist[l][r] << "\n";
}
}
}
