#include <bits/stdc++.h>
#define rep(i,a,b) for (auto i = (a); i <= (b); ++i)
#define Mup(x,y) x = max(x,y)
#define mup(x,y) x = min(x,y)
#define all(x) begin(x),end(x)
#define per(i,a,b) for (auto i = (b); i >= (a); --i)
using namespace std;
using ll = long long;
using ii = pair<int,int>;
#define dbg(...) fprintf(stderr,__VA_ARGS__)
const ll INF = 1e18;
const int N = 1e5+3;
int n, m, x, h[N];
vector<ii> adj[N];
ll dist[N];
int main() {
scanf("%d%d%d", &n, &m, &x);
rep(i,1,n) scanf("%d", &h[i]);
rep(i,1,m) {
int u, v, t;
scanf("%d%d%d", &u, &v, &t);
if (h[u] >= t) adj[u].push_back({v,t});
if (h[v] >= t) adj[v].push_back({u,t});
}
fill(dist,dist+N,INF);
priority_queue<pair<ll,int>> pq;
dist[1] = 0, pq.push({0,1});
while (not empty(pq)) {
auto [d,a] = pq.top(); pq.pop(), d=-d;
if (dist[a] < d) continue;
for (auto [b,w] : adj[a]) {
if (dist[a] < x) {
if (x-dist[a] >= w) {
if (dist[b] > max(dist[a]+w,0LL+x-h[b])) {
dist[b] = max(dist[a]+w,0LL+x-h[b]);
pq.push({-dist[b],b});
}
} else {
if (dist[b] > dist[a]+w+w-(x-dist[a])) {
dist[b] = dist[a]+w+w-(x-dist[a]);
pq.push({-dist[b],b});
}
}
}
else if (dist[b] > dist[a]+2*w) {
dist[b] = dist[a]+2*w;
pq.push({-dist[b],b});
}
}
}
if (dist[n] < x) printf("%lld", h[n]-(x-dist[n]) + dist[n]);
else if (h[n]+dist[n] >= INF) puts("-1");
else printf("%lld", h[n]+dist[n]);
}
