#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstdlib>
using namespace std;
int qw[1000][1000]={0};
int n,m,k,ans;
int main(){
	freopen ("trobot.in","r",stdin);
	freopen ("trobot.out","w",stdout);
	int n,m;
	int a,b,c,d,e,f,k;
	int zheny[10000]={0},jiay[10000]={0};
	cin>>n>>m>>k;
	for(a=1;a<=n;a++)
	{
		cin>>b>>c>>d;
		qw[b][c]=d;
		qw[c][b]=d;
	}
	for(a=1;a<=n;a++)
	{
		
		if(qw[m][a]!=0)
			zheny[a]=qw[m][a];
		else
			zheny[a]=10000000;
	}
	jiay[m]=1;
	int jib;
	for(a=1;a<=n;a++)
	{
		d=0x7FFFFFFF;
		for(b=1;b<=n;b++)
		{
			if(jiay[b]==0&&zheny[b]<d)
			{
				d=zheny[b];
				jib=b;
			}
		}
		jiay[jib]=1;
		for(b=1;b<=n;b++)
		{
			if(jiay[b]==0&&qw[jib][b]<zheny[b]&&qw[jib][b]!=0)
			{
				zheny[b]=qw[jib][b];
			}
		}
	}
	ans=0;
	for(a=1;a<=b;a++)
	{
		if(a!=k)
		ans=ans+zheny[a]*2;
	}
	cout<<ans;
	return 0;
}