#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define R cin>>
#define Z class
#define ll long long
#define ln cout<<'\n'
#define in(a) insert(a)
#define pb(a) push_back(a)
#define pd(a) printf("%.10f\n",a)
#define mem(a) memset(a,0,sizeof(a))
#define all(c) (c).begin(),(c).end()
#define iter(c) __typeof((c).begin())
#define rrep(i,n) for(ll i=(ll)(n)-1;i>=0;i--)
#define REP(i,m,n) for(ll i=(ll)(m);i<(ll)(n);i++)
#define rep(i,n) REP(i,0,n)
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
template<Z A>void pr(A a){cout<<a;ln;}
template<Z A,Z B>void pr(A a,B b){cout<<a<<' ';pr(b);}
template<Z A,Z B,Z C>void pr(A a,B b,C c){cout<<a<<' ';pr(b,c);}
template<Z A,Z B,Z C,Z D>void pr(A a,B b,C c,D d){cout<<a<<' ';pr(b,c,d);}
template<Z A>void PR(A a,ll n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
ll check(ll n,ll m,ll x,ll y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1e9+7,MAXL=1LL<<61,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<ll,ll> P;
ll d[2222][2222];
vector<P> v[2222];

void Main() {
  ll n,m,s1,s2,t;
  cin >> n >> m >> s1 >> s2 >> t;
  s1--,s2--;
  rep(i,m) {
    ll x,y,z;
    cin >> x >> y >> z;
    x--,y--;
    v[x].pb(P(y,z));
    v[y].pb(P(x,z));
  }
  rep(i,n)rep(j,n) d[i][j]=MAXL;
  rep(k,n) {
    priority_queue<P,vector<P>,greater<P> > que;
    d[k][k]=0;
    que.push(P(0,k));
    while(!que.empty()) {
      P p=que.top();que.pop();
      ll x=p.S,c=p.F;
      if(d[k][x]<c) continue;
      rep(i,v[x].size()) {
        P q=v[x][i];
        ll y=q.F,cc=q.S;
        if(d[k][y]>c+cc) {
          d[k][y]=c+cc;
          que.push(P(c+cc,y));
        }
      }
    }
  }
  ll ans=-1;
  if(d[0][s1]+d[s1][s2]+d[s2][0]<=t) ans=max(ans,t);
  rep(i,n) {
    REP(j,i,n) {
      if(d[0][i]+d[i][s1]+d[s1][j]+d[j][0]<=t&&d[0][i]+d[i][s2]+d[s2][j]+d[j][0]<=t) {
        ll c=max(d[i][s1]+d[s1][j],d[i][s2]+d[s2][j]);
        ans=max(ans,t-c);
      }
    }
  }
  pr(ans);
}

int main(){ios::sync_with_stdio(0);cin.tie(0);Main();return 0;}