#include <bits/stdc++.h> using namespace std; const int MAXN = 2e5 + 5, INF = 21e8; int N, Q; pair<int, int> arr[MAXN]; vector<int> v; int graph[MAXN][20]; struct segment{ int tree[4 * MAXN], number[4 * MAXN]; void update(int node, int s, int e, int k, int val, int num){ int mid = (s + e) >> 1; if(s == e){ if(tree[node] > val){ tree[node] = val; number[node] = num; } return; } if(k <= mid) update(node * 2, s, mid, k, val, num); else update(node * 2 + 1, mid + 1, e, k, val, num); if(tree[node * 2] <= tree[node * 2 + 1]) tree[node] = tree[node * 2], number[node] = number[node * 2]; else tree[node] = tree[node * 2 + 1], number[node] = number[node * 2 + 1]; } pair<int, int> query(int node, int s, int e, int l, int r){ int mid = (s + e) >> 1; if(e < l || r < s) return {INF, 0}; if(l <= s && e <= r) return {tree[node], number[node]}; return min(query(node * 2, s, mid, l, r), query(node * 2 + 1, mid + 1, e, l, r)); } }seg; int main(void){ ios_base::sync_with_stdio(false); cin.tie(NULL); int i, j; cin >> N >> Q; for(i = 0;i < 4 * MAXN;i++) seg.tree[i] = INF; for(i = 1;i <= N;i++){ int a, b; cin >> a >> b; arr[i] = {a, b}; v.push_back(a); v.push_back(b); } sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end()); for(i = 1;i <= N;i++){ arr[i].first = (lower_bound(v.begin(), v.end(), arr[i].first) - v.begin()) + 1; arr[i].second = (lower_bound(v.begin(), v.end(), arr[i].second) - v.begin()) + 1; } for(i = 1;i <= N;i++) seg.update(1, 1, 2 * N, arr[i].second, arr[i].first, i); for(i = 1;i <= N;i++){ auto A = seg.query(1, 1, 2 * N, arr[i].first, arr[i].second); graph[i][0] = A.second; //cout << i << " : " << A.second << "\n"; } for(i = 1;i < 20;i++){ for(j = 1;j <= N;j++) graph[j][i] = graph[graph[j][i - 1]][i - 1]; } while(Q--){ int a, b; cin >> a >> b; int ans = 0; if(a == b){ cout << 0 << "\n"; continue; } if(arr[b].second < arr[a].second) { cout << "impossible\n"; continue; } for(i = 19;i >= 0;i--){ if(arr[a].second < arr[graph[b][i]].first) { b = graph[b][i], ans += (1 << i); } } if(arr[b].first > arr[a].second) ans++, b = graph[b][0]; if(arr[b].first > arr[a].second) cout << "impossible\n"; else cout << ans + 1 << "\n"; } return 0; }