#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> v;
typedef vector<v> vv;
typedef vector<vv> vvv;
typedef pair<ll, ll> p;
typedef vector<p> vp;
typedef vector<vp> vvp;
typedef vector<vvp> vvvp;
typedef pair<ll, p> tri;
typedef vector<tri> vtri;
typedef vector<vtri> vvtri;
typedef vector<vvtri> vvvtri;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
#define f first
#define s second
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(),(v).end()
const ll INF = 1e18;
const ll mod = 1e9 + 7;
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
ll N, Q;
cin >> N >> Q;
vp events(N);
for (ll i = 0; i < N; i++) cin >> events[i].f >> events[i].s;
while (Q--)
{
ll s, e;
cin >> s >> e; s--; e--;
queue<p> bfs;
bfs.emplace(s, 0);
vb visited(N, false);
bool done = false;
while (!bfs.empty())
{
auto top = bfs.front();
bfs.pop();
if (visited[top.f]) continue;
visited[top.f] = true;
if (top.f == e)
{
cout << top.s << "\n";
done = true;
break;
}
for (ll i = 0; i < N; i++)
{
if (events[top.f].s >= events[i].f && events[top.f].s <= events[i].s)
{
bfs.emplace(i, top.s + 1);
}
}
}
if (!done) cout << "impossible\n";
}
return 0;
}
