//Challenge: Accepted
#include <bits/stdc++.h>
using namespace std;
#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U> void debug(T a, U ... b){cout << a << " ", debug(b...);}
template<class T> void pary(T l, T r) {
while (l != r) cout << *l << " ", l++;
cout << endl;
}
#else
#define debug(...) 0
#define pary(...) 0
#endif
#define ll long long
#define maxn 200005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
const int inf = 1<<30;
pii seg[maxn];
vector<int> ev[maxn];
bool on[maxn];
int to[17][maxn];
struct query{
int l, r, id;
query(){l = r = id = 0;}
query(int a, int b, int c){l = a, r = b, id = c;}
};
vector<query> que[maxn];
struct BIT{
int bit[maxn];
void modify(int ind, int val) {
for (;ind < maxn;ind += ind & (-ind)) bit[ind] += val;
}
int query(int ind) {
int ret = 0;
for (;ind > 0;ind -= ind &(-ind)) ret += bit[ind];
return ret;
}
} bit;
int ans[maxn];
int main() {
io
int n, q;
cin >> n >> q;
{
vector<int> val;
for (int i = 1;i <= n;i++) {
cin >> seg[i].ff >> seg[i].ss;
val.push_back(seg[i].ff);
val.push_back(seg[i].ss);
}
sort(val.begin(), val.end());
val.resize(int(unique(val.begin(), val.end()) - val.begin()));
for (int i = 1;i <= n;i++) {
seg[i].ff = lower_bound(val.begin(), val.end(), seg[i].ff) - val.begin();
seg[i].ss = lower_bound(val.begin(), val.end(), seg[i].ss) - val.begin();
ev[seg[i].ff].push_back(i);
ev[seg[i].ss].push_back(i);
}
}
seg[0].ss = inf;
priority_queue<pii, vector<pii>, less<pii> > pq;
for (int i = 0;i < 2*n;i++) {
vector<int> tmp;
for (int j:ev[i]) {
if (!on[j]) {
on[j] = 1;
pq.push({seg[j].ss, j});
} else {
tmp.push_back(j);
on[j] = 0;
}
}
while (pq.size() && pq.top().ff <= i) pq.pop();
for (int j:tmp) {
to[0][j] = (pq.size() ? pq.top().ss : 0);
}
}
//pary(to[0], to[0] + n + 1);
for (int i = 1;i < 17;i++) {
for (int j = 0;j <= n;j++) to[i][j] = to[i-1][to[i-1][j]];
}
for (int id = 0;id < q;id++) {
int s, t;
cin >> s >> t;
ans[id] = -1;
if (seg[t].ss >= seg[s].ss) {
if (seg[t].ff <= seg[s].ss) {
if (s == t) ans[id] = 0;
else ans[id] = 1;
} else {
int cur = s, dis = 0;
for (int i = 16;i >= 0;i--) {
if (seg[to[i][cur]].ss < seg[t].ff) {
cur = to[i][cur];
dis += 1<<i;
}
}
ans[id] = dis;
que[seg[cur].ss].push_back(query(seg[t].ff, seg[t].ss, id));
}
}
}
for (int i = 0;i < 2*n;i++) {
for (int j:ev[i]) {
if (!on[j]) {
on[j] = 1;
bit.modify(seg[j].ss, 1);
}
}
for (auto [l, r, id]:que[i]) {
if (bit.query(r) - bit.query(l-1) > 0) ans[id] += 2;
else ans[id] = -1;
}
}
for (int i = 0;i < q;i++) {
if (ans[i] == -1) cout << "impossible\n";
else cout << ans[i] << "\n";
}
}
