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; if (dist[h][u] == c) { 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) { } }