//code by Nobody.Emissary
#include<bits/stdc++.h>

#define ll long long

using namespace std;

namespace IO{
	inline int read(){
		int X=0, W=0; char ch=getchar();
		while(!isdigit(ch)) W|=ch=='-', ch=getchar();
		while(isdigit(ch)) X=(X<<1)+(X<<3)+(ch^48), ch=getchar();
		return W?-X:X;
	}
	inline void write(int x){
		if(x<0) x=-x, putchar('-');
		if(x>9) write(x/10);
		putchar(x%10+'0');
	}
	inline void sprint(int x){write(x), putchar(32);}
	inline void eprint(int x){write(x), putchar(10);}
}using namespace IO;

const int inf = 1e9;
const int MAXN = 5e5+5;

int n, m, s, k;
int fa[MAXN], val[MAXN], maxn[MAXN];

ll ans, tmp1[MAXN], tmp2[MAXN], tot1, tot2;

struct edge{
	int u, v, w;
	inline bool friend operator < (const edge &x, const edge &y){
		return x.w<y.w;
	}
}E[MAXN];

inline int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]);}

inline bool comp(int x, int y){return min(val[x],maxn[x])<min(val[y],maxn[y]);}

inline void merge(int x, int y, int w){
	x=find(x), y=find(y);
	if(x==y) return ;
	if(val[x]<val[y]) swap(x,y);
	maxn[x]=w; fa[x]=y; ans+=w;
	return ;
}

int main(){
	n=read(), m=read(), k=read(), s=read(); int tot=0;
	for(int i=1;i<=n;++i) fa[i]=i, val[i]=inf;
	for(int i=1;i<=m;++i){
		int x, y, w;
		x=read(), y=read(), w=read();
		if(x==s) val[y]=min(val[y],w);
		else if(y==s) val[x]=min(val[x],w);
		else E[++tot]=edge{x,y,w};
	}
	m=tot; sort(E+1,E+1+m); int cnt=0;
	for(int i=1;i<=m;++i)	merge(E[i].u,E[i].v,E[i].w);
	for(int i=1;i<=n;++i){
		if(i==s) continue;
		if(find(i)==i){
			if(val[i]==inf) continue;
			ans+=val[i]; val[i]=inf; ++cnt;
		}
	}
	if(cnt>k) return printf("nonnondayo"), 0; tot=0;
	for(int i=1;i<=n;++i){
		if(val[i]!=inf){
			if(val[i]<maxn[i]) tmp1[++tot1]=i;
			else tmp2[++tot2]=i;
		}
	}
	if(tot1+tot2+cnt<k) return printf("nonnondayo"), 0;
	sort(tmp1+1,tmp1+1+tot1,comp); sort(tmp2+1,tmp2+1+tot2,comp);
	for(int i=1;i<=tot2;++i) tmp1[++tot1]=tmp2[i];
	for(int i=1;i<=k-cnt;++i) ans+=val[tmp1[i]]-maxn[tmp1[i]];
	printf("%lld",ans);
	return 0;
}