#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define all(v) v.begin(), v.end()
const int M = 5000, M1 = 1e5, lg = 17;
int dis[M][M],nx[M][M];
vector<int> nei[M];
void bfs(int u)
{
for (int i=0;i<M;i++) dis[u][i]=M;
dis[u][u]=0;
queue<int> q;
q.push(u);
while (!q.empty())
{
int x=q.front();q.pop();
int cur=x;
while (nx[x][cur]<M)
{
int i=nx[x][cur];
if (dis[u][i]>dis[u][x]+1)
dis[u][i]=dis[u][x]+1,q.push(i);
cur=i;
}
}
}
int dep[M], par[M][lg];
bool vis[M];
void dfs(int u)
{
vis[u]=1;
for (int p=1;(1<<p)<=dep[u];p++)
par[u][p]=par[par[u][p-1]][p-1];
for (int i:nei[u])
par[i][0]=u,dep[i]=dep[u]+1,dfs(i);
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(NULL), cout.tie(NULL);
int n,q;
cin>>n>>q;
if (n<=1000 && q<=100)
{
int s[n],e[n];
for (int i=0;i<n;i++)
cin>>s[i]>>e[i];
for (int i=0;i<n;i++)
{
int p=i;
for (int j=0;j<n;j++)
if (i!=j && s[j]<=e[i] && e[i]<=e[j])
nx[i][p]=j,p=j;
nx[i][p]=M;
}
while (q--)
{
int s1,e1;
cin>>s1>>e1;s1--,e1--;
bfs(s1);
if (dis[s1][e1]==M)
cout<<"impossible"<<endl;
else
cout<<dis[s1][e1]<<endl;
}
}
else
{
int s[n],e[n],ts[n]={};
map<int,vector<pair<int,int>>> mp;
for (int i=0;i<n;i++)
{
cin>>s[i]>>e[i];
mp[s[i]].push_back({i,1});
mp[e[i]].push_back({i,0});
}
set<int> se;
set<pair<int,int>> se1;
for (auto [x,y]:mp)
{
int cnt=0;
for (auto [i,j]:y)
cnt+=1-j;
if (cnt==2)
{
int f=-1;
for (auto [i,j]:y)
if (!j)
{
if (~f)
{
if (ts[f])
nei[i].push_back(f),se1.insert({f,i});
else if(ts[i])
nei[f].push_back(i),se1.insert({i,f});
else
se1.insert({i,f}),se1.insert({f,i});
}
else f=i;
}
}
else if(cnt==1)
{
int u;
for (auto [i,j]:y) if (!j) u=i;
se.erase(u);
if (!se.empty())
nei[*se.begin()].push_back(u),ts[*se.begin()]=1;
}
for (auto [i,j]:y)
if (j) se.insert(i);
else se.erase(i);
}
for (auto [x,y]:mp)
{
for (auto [i,j]:y)
if (!j && !vis[i])
dfs(i);
}
while (q--)
{
int s1,e1;
cin>>s1>>e1;
if (se1.count({s1,e1}))
cout<<1<<endl;
else if(dep[s1]>=dep[e1])
{
int dif=dep[s1]-dep[e1];
for (int p=0;p<lg;p++)
if (dif>>p&1)
s1=par[s1][p];
if (s1==e1)
cout<<dif<<endl;
else
cout<<"impossible"<<endl;
}
else
cout<<"impossible"<<endl;
}
}
return 0;
}
