#include <iostream>
#include <vector>
#include <queue>
#include <stdio.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> Pa;

struct edge{
    ll to,dist;
};

ll N,M,P,Q,T;
ll inf = 1e18;
vector<vector<edge>> v(2010);

void Dijkstra(int s,vector<ll>& dp){
    dp[s] = 0;
    vector<int> used(N+1,0);
    while(true){
        ll u = -1;
        for(int i=1;i<=N;i++){
            if(!used[i] && (u==-1 || dp[i]<dp[u])){
                u = i;
            }
        }
        if(u==-1) break;
        used[u] = 1;
        for(auto x:v[u]){
            dp[x.to] = min(dp[x.to],dp[u]+x.dist);
        }
    }
}

int main(){
    cin >> N >> M >> P >> Q >> T;
    ll a,b,c;
    for(int i=0;i<M;i++){
        scanf("%lld%lld%lld",&a,&b,&c);
        v[a].push_back({b,c});
        v[b].push_back({a,c});
    }
    vector<ll> dp1(N+1,inf),dp2(N+1,inf),dp3(N+1,inf);
    Dijkstra(1,dp1);
    Dijkstra(P,dp2);
    Dijkstra(Q,dp3);
    ll ans = -1;
    for(int i=1;i<N;i++) for(int j=i;j<=N;j++){
        ll t = dp1[i]+dp1[j]+max(dp2[i]+dp2[j],dp3[i]+dp3[j]);
        if(t<=T) ans = max(ans,T-max(dp2[i]+dp2[j],dp3[i]+dp3[j]));
    }
    if(2*(min(dp1[P],dp1[Q])+dp2[Q])<=T) ans = T;
    if(dp1[P]+dp1[Q]+dp2[Q]<=T) ans = T;
    cout << ans << endl;
}