#include<iostream> #include<map> #include<set> #include<utility> #define st first #define ed second #define int int64_t using namespace std; signed main() { int n,q; cin>>n>>q; map<int,set<int>>m; for(int i=0;i<n;i++) { int u,v; cin>>u>>v; m[u].insert(v); } while(q--) { int u,v; cin>>u>>v; if(m[u].count(v)) cout<<1<<endl; else cout<<"impossible"<<endl; } }