#include<bits/stdc++.h>
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
#pragma GCC optimize("Ofast")
#define int long long
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int range_rng(int l, int r)
{
return uniform_int_distribution<int>(l,r)(rng);
}
struct Node
{
int minval;
int minpoz;
};
int s[100005];
int e[100005];
int up[17][100005];//binary lifting pe predecesorii optimi
vector<int> vals;
map<int,int> normie;
int weat;
class AINT
{
public:
Node aint[800005];
Node combine(Node a, Node b)
{
Node c;
if (a.minval<b.minval)
c=a;
else if (b.minval<a.minval)
c=b;
else
{
c.minval=a.minval;
c.minpoz=min(a.minpoz,b.minpoz);
}
return c;
}
void build(int l, int r, int val)
{
if (l==r)
{
aint[val].minval=1e9;
aint[val].minpoz=0;
return;
}
int mid;
mid=(l+r)/2;
build(l,mid,val*2);
build(mid+1,r,val*2+1);
aint[val]=combine(aint[val*2],aint[val*2+1]);
}
void update(int l, int r, int val, int poz, int x, int truepoz)
{
if (l==r && l==poz)
{
aint[val]=combine(aint[val],{x,truepoz});
return;
}
int mid;
mid=(l+r)/2;
if (poz<=mid)
update(l,mid,val*2,poz,x,truepoz);
else
update(mid+1,r,val*2+1,poz,x,truepoz);
aint[val]=combine(aint[val*2],aint[val*2+1]);
}
Node query(int l, int r, int val, int qa, int qb)
{
if (qa<=l && r<=qb)
{
return aint[val];
}
int mid;
Node ans= {1000000000,0};
mid=(l+r)/2;
if (qa<=mid)
ans=combine(ans,query(l,mid,val*2,qa,qb));
if (qb>mid)
ans=combine(ans,query(mid+1,r,val*2+1,qa,qb));
return ans;
}
} sinistrel;
signed main()
{
/*
ifstream fin("arbore.in");
ofstream fout("arbore.out");
*/
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,q,i,j,cnt,st,en,ans;
Node res;
cin >> n >> q;
for (i=1; i<=n; i++)
{
cin >> s[i] >> e[i];
vals.push_back(s[i]);
vals.push_back(e[i]);
}
sort(vals.begin(),vals.end());
cnt=0;
for (i=0; i<vals.size(); i++)
{
if (i==0 || vals[i]!=vals[i-1])
cnt++;
normie[vals[i]]=cnt;
}
sinistrel.build(1,cnt,1);
for (i=1; i<=n; i++)
{
s[i]=normie[s[i]];
e[i]=normie[e[i]];
sinistrel.update(1,cnt,1,e[i],s[i],i);
}
for (i=1; i<=n; i++)
{
weat=i;
res=sinistrel.query(1,cnt,1,s[i],e[i]);
if (res.minpoz==i)
up[0][i]=0;
else
up[0][i]=res.minpoz;
}
for (i=1;i<=16;i++)
{
for (j=1;j<=n;j++)
{
up[i][j]=up[i-1][up[i-1][j]];
}
}
for (i=1; i<=q; i++)
{
cin >> st >> en;
if (st==en)
{
cout << "0\n";
continue;
}
ans=0;
for (j=16; j>=0; j--)
{
if (e[up[j][en]]>e[st])
{
en=up[j][en];
ans+=(1<<j);
}
}
if (s[en]<=e[st] && e[st]<=e[en])
cout << ans+1 << "\n";
else
cout << "impossible\n";
}
return 0;
}
