#pragma GCC optimize("Ofast,unroll-loops")
#include<bits/stdc++.h>
#define int long long
#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define mask(k) (1<<k)
#define mp make_pair
#define checktime cerr << (double)clock() / CLOCKS_PER_SEC * 1000 << " ms";
using namespace std;
#define getchar_unlocked getchar
inline int scan()
{
char c = getchar_unlocked();
int x = 0;
while (c < '0' || c > '9')
{
c = getchar_unlocked();
}
while (c >= '0' && c <= '9')
{
x = (x << 1) + (x << 3) + c - '0';
c = getchar_unlocked();
}
return x;
}
void phongbeo();
const int inf = 1e16;
const ll mod2 = 1e9+7;
const int mod1 = 998244353;
const ll base=67;
int add(int x,int y)
{
if(x+y>=mod2) x-=mod2;
if(x+y<0)x+=mod2;
return x+y;
}
struct icd
{
long double a;
int b;
};
struct ib
{
int a;
int b;
};
struct ic
{
ll a;
int b, c;
};
struct id
{
int a, b, c, d;
};
struct ie
{
int a, b, c, d, e;
};
int n, m, s1, s2, s4, s3, sf, k, s5, s6, mx, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2, r2, center;
int i, s10, s12,k1,k2,k3,s11,lim,w,l,r ;
int kk;
int el = 19;
main()
{
if(fopen(task".inp","r"))
{
fin(task);
fou(task);
}
NHP
/// cin>>s1;
// modwwe
phongbeo();
// checktime
}
int h[100001];
int dist[100001];
vector<ic> v[100001];
struct cmp
{
bool operator()(ic a,ic b)
{
if(a.a==b.a) return a.b>b.b;
return a.a<b.a;
}
};
priority_queue<ic,vector<ic>,cmp>p;
void phongbeo()
{
cin>>n>>m>>k;
for(int i=1; i<=n; i++)
cin>>h[i],dist[i]=-1;
for(int i=1; i<=m; i++)
{
cin>>l>>r>>s2;
v[l].pb({r,s2});
v[r].pb({l,s2});
}
p.push({k,0,1});
while(!p.empty())
{
ic x=p.top();
p.pop();
if(dist[x.c]!=-1) continue;
dist[x.c]=x.b+h[x.c]-x.a;
for(auto f:v[x.c])
{
if(dist[f.a]!=-1) continue;
if(x.a<=f.b)
{
if(f.b<=h[x.c])
p.push({0,x.b+f.b-x.a+f.b,f.a});
}
else
{
p.push({min(x.a-f.b,h[f.a]),x.b+max(f.b,x.a-h[f.a]),f.a});
}
}
}
cout<<dist[n];
}
