#include using namespace std; #define ll long long const ll mod=1000000007; int a[4004]; pair aa[8000000]; int main(){ // int n; cin>>n; // for(int i=0;i>a[i]; int n=4000; srand(time(0)); for(int i=0;i st; for(int ii=0;ii>()); set rng; rng.insert({-1,ptr}); for(int i=0;i