#include <bits/stdc++.h> using namespace std; using ll = long long; struct Segtree { vector<ll> seg; vector<ll> A; ll size; Segtree(ll n, vector<ll> B){ size = n; seg.resize(4*n, -1); A = B; } void __update(ll n, ll l, ll r, ll i, ll val){ if(l > i || r < i) return; if(l == i && r == i){ if(seg[n] == -1 || A[seg[n]] > A[val]) seg[n] = val; return; } ll m = (l+r)/2; __update(2*n, l, m, i, val); __update(2*n+1, m+1, r, i, val); if(seg[2*n] == -1) seg[n] = seg[2*n+1]; else if(seg[2*n+1] == -1) seg[n] = seg[2*n]; else{ if(A[seg[2*n]] < A[seg[2*n+1]]) seg[n] = seg[2*n]; else seg[n] = seg[2*n+1]; } } void update(ll i, ll val){ __update(1, 1, size, i, val); } ll __query(ll n, ll l, ll r, ll left, ll right){ if(l > right || r < left) return -1; if(l >= left && r <= right) return seg[n]; ll m = (l+r)/2; ll a = __query(2*n, l, m, left, right); ll b = __query(2*n+1, m+1, r, left, right); if(a == -1) return b; if(b == -1) return a; if(A[a] < A[b]) return a; else return b; } ll query(ll left, ll right){ return __query(1, 1, size, left, right); } }; int main(){ ll n,q;cin>>n>>q; vector<pair<ll, ll>> A(n); for(pair<ll, ll> &i:A) cin>>i.first>>i.second; vector<ll> compress(2*n); for(ll i=0;i<n;i++){ compress[2*i] = A[i].first; compress[2*i+1] = A[i].second; } sort(compress.begin(), compress.end()); map<ll, ll> cmprs; ll cnt=0; for(ll i=0;i<2*n;i++){ if(i == 2*n-1 || compress[i] != compress[i+1]){ cmprs[compress[i]] = cnt++; } } for(ll i=0;i<n;i++){ A[i].first = cmprs[A[i].first]; A[i].second = cmprs[A[i].second]; } vector<ll> B(n); for(ll i=0;i<n;i++) B[i] = A[i].first; Segtree seg(2*n, B); for(ll i=0;i<n;i++){ seg.update(A[i].second, i); } vector<ll> prev(n); for(ll i=0;i<n;i++){ prev[i] = seg.query(A[i].first, A[i].second); } vector<vector<ll>> jump(n, vector<ll>(20)); for(ll i=0;i<n;i++){ jump[i][0] = prev[i]; } for(ll i=1;i<20;i++){ for(ll j=0;j<n;j++){ jump[j][i] = jump[jump[j][i-1]][i-1]; } } while(q--){ ll a,b;cin>>a>>b;a--,b--; if(a == b){ cout << 0 << '\n'; continue; } if(A[a].second > A[b].second){ cout << "impossible\n"; continue; } ll cnt=1; while(A[a].second < A[b].first){ ll j; for(j=0;j<20;j++){ if(A[jump[b][j]].first < A[a].second){ j--; break; } } if(j == 20) break; if(j == -1) j = 0; cnt += 1ll << j; b = jump[b][j]; } if(A[a].second < A[b].first){ cout << "impossible\n"; } else{ cout << cnt << '\n'; } } }