#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
template<class T>void maximize(T& a, T b){
if(a < b){
a = b;
}
}
const int lim = 1e5 + 5;
int n, q, l[lim], r[lim];
namespace sub2{
void solve(){
for(int _ = 0; _ < q; _++){
int s, e;
cin >> s >> e;
queue<int>Q;
Q.push(s);
vector<int>f(n + 1, -1);
f[s] = 0;
while(!Q.empty()){
int u = Q.front();
Q.pop();
for(int v = 1; v <= n; v++){
if(f[v] == -1 && l[v] <= r[u] && r[v] >= r[u]){
f[v] = f[u] + 1;
Q.push(v);
}
}
}
if(f[e] == -1){
cout << "impossible\n";
continue;
}
cout << f[e] << "\n";
}
}
}
namespace sub13456{
const int LG = 17;
vector<int>comp(1, -1);
int get_id(int x){
return lower_bound(comp.begin(), comp.end(), x) - comp.begin();
}
int get_min_pos(int i, int j){
return l[i] < l[j] ? i : j;
}
int lgv[lim << 1], up[LG][lim], spt[LG + 1][lim << 1];
int get_spt(int l, int r){
int k = lgv[r - l + 1];
return get_min_pos(spt[k][l], spt[k][r - (1 << k) + 1]);
}
void solve(){
lgv[0] = -1;
for(int i = 1; i < (lim << 1); i++){
lgv[i] = lgv[i >> 1] + 1;
}
comp.insert(comp.end(), l + 1, l + n + 1);
comp.insert(comp.end(), r + 1, r + n + 1);
sort(comp.begin(), comp.end());
comp.resize(unique(comp.begin(), comp.end()) - comp.begin());
int N = (l[0] = comp.size()) - 1;
memset(spt, up[0][0] = 0, sizeof(spt));
for(int i = 1; i <= n; i++){
l[i] = get_id(l[i]);
r[i] = get_id(r[i]);
spt[0][r[i]] = get_min_pos(spt[0][r[i]], i);
}
for(int i = 1; i <= LG; i++){
for(int j = 1; j + (1 << i) - 1 <= N; j++){
spt[i][j] = get_min_pos(spt[i - 1][j], spt[i - 1][j + (1 << (i - 1))]);
}
}
for(int i = 1; i <= n; i++){
up[0][i] = get_spt(l[i], r[i]);
}
for(int i = 1; i < LG; i++){
for(int j = 0; j <= n; j++){
up[i][j] = up[i - 1][up[i - 1][j]];
}
}
for(int _ = 0; _ < q; _++){
int s, e, ans = 0;
cin >> s >> e;
if(s == e){
cout << "0\n";
continue;
}
if(l[e] <= r[s] && r[e] >= r[s]){
cout << "1\n";
continue;
}
if(r[s] > r[e]){
cout << "impossible\n";
continue;
}
for(int bit = LG - 1; bit > -1; bit--){
int ne = up[bit][e];
if(ne != 0 && l[ne] > r[s]){
ans |= 1 << bit;
e = ne;
}
}
if(l[up[0][e]] > r[s]){
cout << "impossible\n";
continue;
}
cout << ans + 2 << "\n";
}
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if(fopen(taskname".inp", "r")){
freopen(taskname".inp", "r", stdin);
}
cin >> n >> q;
for(int i = 1; i <= n; i++){
cin >> l[i] >> r[i];
}
if(n <= 1000 && q <= 100){
sub2::solve();
}
else{
sub13456::solve();
}
}
