#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll, ll>
#define fi first
#define sec second
#define ld long double
const int MAXN = 5e3;
const ll INF = 4e18;
const int MOD = 998244353;
ll S[MAXN + 5], E[MAXN + 5];
ll dp[MAXN + 5][MAXN + 5];
vector<pii> edges[MAXN + 5];
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
for(;tc--;){
ll N, Q; cin >> N >> Q;
vector<pair<pii, ll>> segments(1);
for(int i = 1; i <= N; i++){
cin >> S[i] >> E[i];
segments.push_back({{S[i], E[i]}, i});
}
sort(segments.begin(), segments.end(), [&](pair<pii, ll> a, pair<pii, ll> b){
if(a.fi.sec == b.fi.sec) return a.fi.fi < b.fi.fi;
return a.fi.sec < b.fi.sec;
});
for(int i = 1; i <= N; i++){
for(int j = i + 1; j <= N; j++){
if(segments[j].fi.fi <= segments[i].fi.sec && segments[i].fi.sec <= segments[j].fi.sec){
edges[i].push_back({segments[j].fi.sec, segments[j].sec});
// cout << segments[i].sec << " " << segments[j].fi.sec << " edges\n";
}
}
sort(edges[i].begin(), edges[i].end());
}
for(int i = 1; i <= N; i++){
for(int j = 1; j <= N; j++) dp[i][j] = INF;
}
for(int len = 1; len <= N; len++){
for(int j = 1; j <= N - len + 1; j++){
ll L = j, R = j + len - 1;
if(len == 1){
dp[segments[L].sec][segments[R].sec] = 0;
}
else{
if(segments[R].fi.fi <= segments[L].fi.sec && segments[L].fi.sec <= segments[R].fi.sec){
dp[segments[L].sec][segments[R].sec] = 1;
}
else{
// ambil segment terjauh, yang masih S[x] <= E[L] dan E[x] <= S[R]
pii now = {segments[R].fi.sec, INF};
auto it = upper_bound(edges[L].begin(), edges[L].end(), now);
if(it != edges[L].begin()){
--it;
dp[segments[L].sec][segments[R].sec] = dp[(*it).sec][segments[R].sec] + 1;
}
}
}
// cout << dp[segments[L].sec][segments[R].sec] << " " << segments[L].sec << " " << segments[R].sec << "\n";
}
}
for(int i = 1; i <= Q; i++){
ll a, b; cin >> a >> b;
if(E[a] == E[b]){
if(a == b) cout << 0 << "\n";
else cout << 1 << "\n";
continue;
}
if(dp[a][b] >= INF) cout << "impossible\n";
else cout << dp[a][b] << "\n";
}
}
}
/*
*/
