#include <bits/stdc++.h>
using namespace std;
#define int long long
#define a2 array <int,2>
#define a3 array <int,3>
const int N=1e5+5;
const int INF=1e15+7;
int n,m,st_pos,d[N],h[N],p[N],tt;
vector <a2> adj[N];
priority_queue <a3,vector <a3>,greater <a3>> pq; // -d_u , u;
signed main()
{
memset(d,-1,sizeof(d));
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m >> st_pos;
for(int i=1;i<=n;i++) cin >> h[i];
for(int i=1;i<=m;i++){
int u,v,w;
cin >> u >> v >> w;
adj[u].push_back({v,w});
adj[v].push_back({u,w});
}
pq.push({0,st_pos,1});
while(!pq.empty()){
auto [d_u,pos,u]=pq.top();
pq.pop();
if(u==n){
cout << d_u+h[u]-pos;
exit(0);
}
if(d[u]!=-1) continue;
d[u]=d_u;
for(auto [v,w]:adj[u]){
if(d[v]==-1 && w<=h[u]){
if(pos<w) pq.push({d_u+w+w-pos,0,v});
else if(pos-w>h[v]) pq.push({d_u+pos-h[v],h[v],v});
else pq.push({d_u+w,pos-w,v});
}
}
}
cout << -1;
}
