#include using namespace std; typedef long long signed int LL; typedef long long unsigned int LU; #define incID(i, l, r) for(int i = (l) ; i < (r); i++) #define incII(i, l, r) for(int i = (l) ; i <= (r); i++) #define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--) #define decII(i, l, r) for(int i = (r) ; i >= (l); i--) #define inc(i, n) incID(i, 0, n) #define inc1(i, n) incII(i, 1, n) #define dec(i, n) decID(i, 0, n) #define dec1(i, n) decII(i, 1, n) #define inII(v, l, r) ((l) <= (v) && (v) <= (r)) #define inID(v, l, r) ((l) <= (v) && (v) < (r)) #define PB push_back #define EB emplace_back #define MP make_pair #define FI first #define SE second #define PQ priority_queue #define ALL(v) v.begin(), v.end() #define RALL(v) v.rbegin(), v.rend() #define FOR(it, v) for(auto it = v.begin(); it != v.end(); ++it) #define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it) template bool setmin(T & a, T b) { if(b < a) { a = b; return true; } else { return false; } } template bool setmax(T & a, T b) { if(b > a) { a = b; return true; } else { return false; } } template bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } } template bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } } template T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); } template T lcm(T a, T b) { return a / gcd(a, b) * b; } // ---- ---- template class RPQ : public PQ, greater> { }; template void dijkstra(int start, vector> g[], Cost dist[]) { RPQ> q; dist[start] = 0; q.emplace(dist[start], start); while(! q.empty()) { auto cp = q.top(); q.pop(); int p = cp.SE; Cost c = cp.FI; if(dist[p] != c) { continue; } for(auto && e : g[p]) { int ep = e.FI; Cost ec = e.SE; if(setmin(dist[ep], dist[p] + ec)) { q.emplace(dist[ep], ep); } } } return; } LL n, m, k, s, t, a[200000], b[200000], c[200000], d[400002], INF = 1e15; set> se[200000]; vector> v[400002]; int main() { cin >> n >> m >> k >> s >> t; inc(i, m) { cin >> a[i] >> b[i] >> c[i]; a[i]--; } inc(i, m) { se[a[i] + 0].emplace(b[i], 2 * i + 0); se[a[i] + 1].emplace(c[i], 2 * i + 1); } se[ 0].emplace(s, 2 * m + 0); se[n - 1].emplace(t, 2 * m + 1); inc(i, 2 * m + 2) { d[i] = INF; } inc(i, m) { v[2 * i + 0].EB(2 * i + 1, 0); } inc(i, n) { se[i].emplace(INF, -1); FOR(it, se[i]) { auto ne = it; ++ne; if(ne -> SE == -1) { break; } v[it -> SE].EB(ne -> SE, abs((it -> FI) - (ne -> FI))); v[ne -> SE].EB(it -> SE, abs((it -> FI) - (ne -> FI))); } } dijkstra(2 * m + 0, v, d); cout << (d[2 * m + 1] < INF ? d[2 * m + 1] : -1) << endl; return 0; }