import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.complex, std.container, std.math, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum INF = 10L^^18;

int N, M, P, Q;
long T;
int[] A, B;
long[] C;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      M = readInt();
      P = readInt() - 1;
      Q = readInt() - 1;
      T = readLong();
      A = new int[M];
      B = new int[M];
      C = new long[M];
      foreach (i; 0 .. M) {
        A[i] = readInt() - 1;
        B[i] = readInt() - 1;
        C[i] = readLong();
      }
      
      auto graph = new int[][N];
      foreach (i; 0 .. M) {
        graph[A[i]] ~= i;
        graph[B[i]] ~= i;
      }
      
      const srcs = [0, P, Q];
      auto dist = new long[][](3, N);
      foreach (h; 0 .. 3) {
        alias Node = Tuple!(long, "c", int, "u");
        BinaryHeap!(Array!Node, "a > b") q;
        dist[h][] = INF;
        dist[h][srcs[h]] = 0;
        q.insert(Node(0, srcs[h]));
        for (; !q.empty; ) {
          const c = q.front.c;
          const u = q.front.u;
          q.removeFront;
          foreach (i; graph[u]) {
            const cc = c + C[i];
            const v = A[i] ^ B[i] ^ u;
            if (dist[h][v] > cc) {
              dist[h][v] = cc;
              q.insert(Node(cc, v));
            }
          }
        }
      }
      debug {
        foreach (h; 0 .. 3) {
          writeln(dist[h]);
        }
      }
      
      long ans = -1;
      if (dist[0][P] + dist[1][Q] + dist[2][0] <= T) {
        chmax(ans, T);
      }
      foreach (u; 0 .. N) foreach (v; 0 .. N) {
        if (dist[0][u] + dist[1][u] + dist[1][v] + dist[0][v] <= T &&
            dist[0][u] + dist[2][u] + dist[2][v] + dist[0][v] <= T) {
          chmax(ans, T - max(dist[1][u] + dist[1][v], dist[2][u] + dist[2][v]));
        }
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}