#include <cstdio>
using namespace std;

int way[1050]={0},map[1050][1049],que[1102500],dad[1102500];
double x[1050],y[1050],r[1050],spe[1102500];
bool used[1050]={false};

int main(void)
{
	freopen("baler.in","r",stdin);
	freopen("baler.out","w",stdout);
	int i,j,n,st,en,tail=0,head=0,temp;
	double xt,yt,total=0;
	scanf("%d %lf %lf\n",&n,&xt,&yt);
	for (i=0;i<n;i++)
	{
		scanf("%lf %lf %lf\n",&x[i],&y[i],&r[i]);
		if (x[i]==0&&y[i]==0)
			st=i;
		if (x[i]==xt&&y[i]==yt)
			en=i;
		for (j=0;j<i;j++)
			if ((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j])==(r[i]+r[j])*(r[i]+r[j]))
			{
				map[i][way[i]++]=j;
				map[j][way[j]++]=i;
			}
	}
	que[0]=st;
	spe[0]=10000;
	dad[0]=-1;
	used[st]=true;
	while (tail<=head)
	{
		for (i=0;i<way[que[tail]];i++)
			if (!used[map[que[tail]][i]])
			{
				head++;
				que[head]=map[que[tail]][i];
				spe[head]=spe[tail]*r[que[tail]]/r[que[head]];
				dad[head]=tail;
				used[que[head]]=true;
				if (que[head]==en)
				{
					temp=head;
					while (temp!=-1)
					{
						total+=spe[temp];
						temp=dad[temp];
					}
					printf("%.0lf\n",total);
					fclose(stdin);
					fclose(stdout);
					return(0);
				}
			}
		tail++;
	}
	fclose(stdin);
	fclose(stdout);
	return(0);
}