#include 
#include 
#include 
#include 
#include 
using namespace std;
struct node
{
    int idx;
    double dis;
    node(int _idx, double _dis)
    {
        idx=_idx;
        dis=_dis;
    }
    bool operator < (const node &tmp) const
    {
        return dis> tmp.dis;
    }
};
int main()
{
    int n,x,y;
    cin>>n;
    vector>v;
    vector>par[n+5];
    for(int i=0;i>x>>y;
        v.push_back({x,y});
    }
    for(int i=0;iQ;
    Q.push(node(0,0));
    double d[n+5];
    bool vis[n];
    for(int j=0;j