#include <bits/stdc++.h>
//#define int long long
using namespace std;
int N,Q,S[5001],E[5001],X,Y;
bool ADJ[5001][5001],VIS[5001];
int DIST[5001][5001];
void BFS(int x,int DIS = 0){
for(int i = 0;i <= 5000; i += 1)VIS[i] = 0;
queue<pair<int,int>>Q;
Q.push({x,0});
while(Q.size()){
int V = Q.front().first, S = Q.front().second;
Q.pop();
if(VIS[V])continue;
VIS[V] = 1;
DIST[x][V] = S;
for(int i = 0; i <= 5000; i += 1)if(ADJ[V][i])Q.push({i, S + 1});
}
}
int32_t main()
{
cin.tie(0),iostream::sync_with_stdio(0);
cin>>N>>Q;
for(int i = 0; i <= 5000; i += 1)for(int l = 0; l <= 5000; l += 1)DIST[i][l] = -1;
for(int i = 0; i < N; i += 1){
cin>>S[i]>>E[i];
}
for(int i = 0; i < N; i += 1){
for(int l = 0; l < N; l += 1){
ADJ[i][l] = ((S[l] <= E[i]&&E[i]<=E[l])?1:0);
}
}
for(int i = 0; i < N; i += 1)BFS(i);
while(Q--){
cin>>X>>Y;
(DIST[X - 1][Y - 1] == -1?cout<<"impossible\n":cout<<DIST[X - 1][Y - 1]<<'\n');
}
}
