C++ :

#define MAXN 1100UL

#define D(x) ((double)(x))

#include <cstdio>
#include <queue>
#include <cmath>

using namespace std;

queue<int> que;

int x[MAXN],y[MAXN],r[MAXN],p,s,t,n,xt,yt;

bool ex[MAXN];

double dx[MAXN][2],eps=0.1;

double ABS(double a){
	return a>0?a:-a;
}

double Cal(int a,int b){
	return sqrt(D(x[a]-x[b])*D(x[a]-x[b])+D(y[a]-y[b])*D(y[a]-y[b]));
}

int main(){
	scanf("%d%d%d",&n,&xt,&yt);
	for(int i=1;i<=n;i++){
		scanf("%d%d%d",&x[i],&y[i],&r[i]);
		if(x[i]==0&&y[i]==0){
			s=i;
		}
		else if(x[i]==xt&&y[i]==yt){
			t=i;
		}
	}
	//bfs
	dx[s][0]=dx[s][1]=10000.0;
	que.push(s);ex[s]=1;
	while(!que.empty()){
		p=que.front();que.pop();
		for(int i=1;i<=n;i++){
			if(!ex[i]&&i!=p){
				if(ABS(D(r[i]+r[p])-Cal(i,p))<=eps){
					ex[i]=1;dx[i][0]=dx[p][0]*D(r[p])/D(r[i]);
					dx[i][1]=dx[i][0]+dx[p][1];
					if(i==t){
						printf("%d",(int)dx[t][1]);
						return 0;
					}
					que.push(i);
				}
			}
		}
	}
	return 0;
}