#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <numeric>
#include <deque>
#include <random>
#include <unordered_map>
#include <unordered_set>
#include <queue>
#include <stack>
#include <string>
#include <iomanip>
#include <fstream>
#include <bitset>
#include <ctime>
#include <cstdio>
#include <chrono>
#include <functional>
#include <x86intrin.h>
#include <cassert>
#include <list>
#include <iterator>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
#define int long long
#ifdef LOCAL
bool local = true;
#else
bool local = false;
#endif
/*<-------DEFINES START------->*/
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define for1(n) for (int i = 1; i < n; ++i)
#define for0(n) for (int i = 0; i < n; ++i)
#define rep(i, j, n) for (int i = (j); i < (n); ++i)
#define rrep(i, j, n) for (int i = (j); i >= (n); --i)
#define debug(fmt, ...) \
fprintf(stderr, "[%d] " fmt "\n", LINE, ##__VA_ARGS__)
#define lb lower_bound
#define ub upper_bound
#define rsun(a) a.resize(unique(a.begin(), a.end())-a.begin())
#define re return
#define con continue
#define pb push_back
#define pob pop_back;
#define sz(x) (int)size(x)
#define fi first
#define se second
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vi = vector<int>;
using vll = vector<long long>;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
using vvi = vector<vector<int>>;
using vvvi = vector<vector<vector<int>>>;
using vvll = vector<vector<long long>>;
using vpii = vector<pair<long long, long long>>;
using vvpii = vector<vpii>;
using tiii = tuple<int, int, int>;
/*<-------DEFINES END------->*/
/*<-------TEMPLATES START------->*/
template<typename T>
istream& operator>>(istream& in, vector<T>& a) {
for (T& i : a) in >> i;
return in;
}
template<typename T1, typename T2>
istream& operator>>(istream& in, pair<T1, T2>& a) {
in >> a.fi >> a.se;
return in;
}
template<typename T1, typename T2>
ostream& operator<<(ostream& out, pair<T1, T2>& a) {
out << a.fi << " " << a.se;
return out;
}
template<typename T1, typename T2> istream& operator>>(istream& in, vector<pair<T1, T2>>& a) {
for (pair<T1, T2>& i : a)
in >> i.fi >> i.se;
return in;
}
template<typename T> ostream& operator<<(ostream& out, const vector<T>& a) {
for (auto i : a) {
out << i << " ";
}
return out;
}
template<typename T1, typename T2> ostream& operator<<(ostream& out, vector<pair<T1, T2>>& a) {
for (pair<T1, T2> i : a)
out << i.fi << " " << i.se << endl;
return out;
}
template<typename T1> ostream& operator<<(ostream& out, vector<vector<T1>>& a) {
for (vector<T1> i : a) {
for (T1 j : i) out << j << " ";
out << endl;
}
return out;
}
template<typename T1, typename T2> inline T1 min(T1 a, T2 b) {
b = (T1)b;
return a > b ? b : a;
}
template<typename T1, typename T2> inline T1 max(T1 a, T2 b) {
b = (T1)b;
return a > b ? a : b;
}
template<typename T1, typename T2> inline void amin(T1& a, T2 b) {
a = min(a, b);
}
template<typename T1, typename T2> inline void amax(T1& a, T2 b) {
a = max(a, b);
}
/*<-------TEMPLATES END------->*/
double getTime() {
return clock() / (double)CLOCKS_PER_SEC;
}
int randint(int start, int end) {
return rand() % (end - start + 1) + start;
}
ll gcd(ll a, ll b) {
if (a == 0) {
return b;
}
return gcd(b % a, a);
}
ll gcd(ll a, ll b, ll& x, ll& y) {
if (a == 0) {
x = 0;
y = 1;
return b;
}
ll x1, y1, g = gcd(b % a, a, x1, y1);
// (b % a) * x1 + a * y1 = g
// a * x + b * y = g
x = y1 - (b / a * x1);
y = x1;
return g;
}
ll bin_pow(ll a, ll b, ll MOD) {
if (b == 0) {
return 1 % MOD;
}
if (b % 2 == 0) {
ll p = bin_pow(a, b / 2, MOD) % MOD;
return p * p % MOD;
}
return a * bin_pow(a, b - 1, MOD) % MOD;
}
string run_num;
void solve(int t);
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
if (local) {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
// cin >> run_num;
int tt = 1;
// cin >> tt;
rep(i, 1, tt + 1) {
if (local) {
cout << "Case #" << i << ":\n";
}
solve(i);
}
if (local) {
cout << "\n";
cout << fixed << "Time = " << getTime() << " ms\n";
}
return 0;
}
/*<-------ACTUAL CODE STARTS HERE------->*/
#pragma GCC optimize("unroll-loops,Ofast")
const int INF = 2e18, MOD = 1e9 + 7;
const int N = 1e4 + 1000;
struct ST {
vpii t;
void init(int n) {
t.assign(4 * (n + 100), {INF, INF});
}
void build(int v, int tl, int tr, vi& a) {
if (tl + 1 == tr) {
t[v] = {a[tl], tl}; re;
}
int tm = (tl + tr) / 2;
build(2 * v + 1, tl, tm, a);
build(2 * v + 2, tm, tr, a);
t[v] = min(t[2 * v + 1], t[2 * v + 2]);
}
pii get(int v, int tl, int tr, int l, int r) {
if (r <= tl || tr <= l) re {INF, INF};
if (l <= tl && tr <= r) re t[v];
int tm = (tl + tr) / 2;
pii left = get(2 * v + 1, tl, tm, l, r),
right = get(2 * v + 2, tm, tr, l, r);
re min(left, right);
}
};
vpii vec;
vvi gr;
vvi bin_ups;
void dfs(int u, int p) {
bin_ups[0][u] = p;
rep(i, 1, 20) {
bin_ups[i][u] = bin_ups[i - 1][bin_ups[i - 1][u]];
}
for (int v : gr[u]) {
if (v != p) {
dfs(v, u);
}
}
}
pii la(int u, int left, int right) {
int cnt = 0;
rrep(i, 19, 0) {
auto [l1, r1] = vec[bin_ups[i][u]];
if (l1 > right) {
cnt += 1ll << i;
u = bin_ups[i][u];
}
}
re {u, cnt};
}
void solve(int test) {
int n, q; cin >> n >> q;
vec.resize(n); cin >> vec;
map<pii, int> mp;
map<int, int> mp2;
vi cords;
for (auto [l, r] : vec) cords.pb(l), cords.pb(r);
sort(all(cords)); rsun(cords);
for (auto& [l, r] : vec) {
int x = lb(all(cords), l) - cords.begin();
int y = lb(all(cords), r) - cords.begin();
mp2[x] = l;
mp2[y] = r;
l = lb(all(cords), l) - cords.begin();
r = lb(all(cords), r) - cords.begin();
}
rep(i, 0, n) {
mp[vec[i]] = i;
}
vi right(2 * n + 10, INF);
for (auto [l, r] : vec) {
amin(right[r], l);
}
ST t;
t.init(2 * n + 10);
t.build(0, 0, 2 * n + 10, right);
gr.resize(n);
vi roots;
rep(i, 0, n) {
auto [l, r] = vec[i];
auto [l1, r1] = t.get(0, 0, 2 * n + 10, l, r + 1);
if (l1 != l) {
// cout << i << " " << mp[{l1, r1}] << "!!!!\n";
gr[i].pb(mp[{l1, r1}]);
gr[mp[{l1, r1}]].pb(i);
} else {
roots.pb(i);
}
}
bin_ups.assign(20, vi(n + 1));
for (int u : roots) {
dfs(u, u);
}
rep(i, 0, q) {
int u, v; cin >> u >> v;
u--, v--;
if (u == v) {
cout << 0 << "\n"; con;
}
auto [l, r] = vec[u];
auto [l3, r3] = vec[v];
if (r > r3) {
cout << "impossible\n"; con;
}
auto [vrtx, cnt] = la(v, l, r);
auto [l1, r1] = vec[vrtx];
if (l1 <= r && r <= r1) {
cout << cnt + 1 << "\n"; con;
}
auto [l2, r2] = vec[bin_ups[0][vrtx]];
// cout << mp2[l1] << " " << mp2[r1] << " " << mp2[l2] << " " << mp2[r2] << "!!!!!\n";
if (r >= l2) {
cout << cnt + 2 << "\n";
} else {
cout << "impossible\n";
}
}
}
