#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
typedef vector<vpii> vvpii;
typedef tuple<int, int, int> tiii;
typedef vector<tiii> vtiii;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
struct event
{
int s, e, idx;
};
struct segtree
{
vpii arr;
int size;
void init(vector<event> &E)
{
size = 1;
while (size < sz(E))
size *= 2;
arr.assign(2 * size, {INT_MAX, -1});
for (int i = 0; i < sz(E); ++i)
arr[i + size] = {E[i].s, E[i].idx};
}
void setMin(int l, int r, pii v)
{
setMin(l, r, v, 1, 0, size);
}
void setMin(int l, int r, pii v, int x, int lx, int rx)
{
if (l <= lx && rx <= r)
{
arr[x] = min(arr[x], v);
return;
}
if (r <= lx || rx <= l)
return;
int m = (lx + rx) / 2;
setMin(l, r, v, 2 * x, lx, m);
setMin(l, r, v, 2 * x + 1, m, rx);
}
pii queryMin(int i) { return queryMin(i, 1, 0, size); }
pii queryMin(int i, int x, int lx, int rx)
{
if (rx - lx == 1)
return arr[x];
int m = (lx + rx) / 2;
pii tmp;
if (i < m)
tmp = queryMin(i, 2 * x, lx, m);
else
tmp = queryMin(i, 2 * x + 1, m, rx);
return min(tmp, arr[x]);
}
};
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
int N, Q;
cin >> N >> Q;
vector<event> E(N);
vpii Eb(N);
for (int i = 0; i < N; ++i)
{
cin >> E[i].s >> E[i].e;
E[i].idx = i;
Eb[i] = {E[i].s, E[i].e};
}
sort(all(E), [](event a, event b)
{ return a.s < b.s; });
vi posInSeg(N);
for (int i = 0; i < N; ++i)
posInSeg[E[i].idx] = i;
segtree seg;
seg.init(E);
vvi vorg(N, vi(ceil(log2(N)) + 1));
auto cmp = [&](int a, int b)
{ if (Eb[a].second == Eb[b].second) return Eb[a].first > Eb[b].first; else return Eb[a].second > Eb[b].second; };
priority_queue<int, vi, decltype(cmp)> pq(cmp);
for (int i = 0; i < N; ++i)
pq.push(i);
int pointerI = 0;
while (!pq.empty())
{
// move border of starts
int nextBorder = Eb[pq.top()].second;
while (pointerI < sz(E) && E[pointerI].s <= nextBorder)
++pointerI;
// add correspondinge elements to segtree
// TODO: I guess there is no need for a second queue todo
int idx = pq.top();
pq.pop();
seg.setMin(0, pointerI, {Eb[idx].first, idx});
vorg[idx][0] = seg.queryMin(posInSeg[idx]).second;
}
for (int j = 1; j < sz(vorg[0]); ++j)
for (int i = 0; i < N; ++i)
vorg[i][j] = vorg[vorg[i][j - 1]][j - 1];
for (int q = 0, s, e; q < Q; ++q)
{
cin >> s >> e;
--s, --e;
if (s == e)
{
cout << 0 << "\n";
continue;
}
if (Eb[e].first <= Eb[s].second)
{
if (Eb[s].second <= Eb[e].second)
cout << 1 << "\n";
else // then (Eb[s].second > Eb[e].second)
cout << "impossible\n";
continue;
}
int ans = 0;
int tmp = e;
for (int j = sz(vorg[tmp]) - 1; j >= 0; --j)
{
tmp = vorg[e][j];
if (Eb[s].second < Eb[tmp].first)
{
e = tmp;
ans += (1 << j);
}
}
tmp = vorg[e][0];
if (Eb[tmp].first <= Eb[s].second)
cout << ans + 2 << "\n";
else
cout << "impossible\n";
}
return 0;
}
