#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl '\n'
int n;
const int N = 5000, M = 12502501;
int head[N],to[M],nxt[M],ne;
void add(int a,int b){
    to[ne] = b;
    nxt[ne] = head[a];
    head[a] = ne++;
}
vector<int> bfs(int src){
    queue<int> q;
    q.push(src);
    vector<int> dep(n,1e9);
    dep[src] = 0;
    while(q.size()){
        int node = q.front();       q.pop();
        for(int e=head[node];~e;e=nxt[e]){
            int ch = to[e];
            if(dep[ch] != 1e9) continue;
            q.push(ch);
            dep[ch] = dep[node] + 1;
        }
    }
    return dep;
}
void solve(){
    int q;
    cin>>n>>q;
    pair<int,int> v[n];
    for(auto &[s,e] : v) cin>>s>>e;
    memset(head,-1,sizeof(head));
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(i == j) continue;
            if(v[j].first<=v[i].second&&v[i].second<=v[j].second) add(i,j);
        }
    }
    vector<vector<int>> dis(n);
    for(int src=0;src<n;src++) dis[src] = bfs(src);
    while(q--){
        int s,e;
        cin>>s>>e;
        int ans = dis[s-1][e-1];
        if(ans == 1e9) cout<<"impossible"<<endl;
        else cout<<ans<<endl;
    }
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);      cout.tie(0);
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}