#include <bits/stdc++.h>
using namespace std;
//#define int long long
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
signed main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int n,m,k; cin>>n>>m>>k;
    vector<vector<int>> adj(n+1);
    while(m--)
    {
        int a,b; cin>>a>>b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    int inf=1e7;
    vector<vector<int>> dist(n+1, vector<int> (n+1, inf));
    for(int i=1; i<=n; i++)
    {
        dist[i][i]=0;
        queue<int> q;
        q.push(i);
        while(!q.empty())
        {
            int cs=q.front();
            q.pop();
            for(int &j:adj[cs])
                if(dist[i][cs]+1<dist[i][j])
            {
                dist[i][j]=dist[i][cs]+1;
                q.push(j);
            }
        }
    }
    int l; cin>>l;
    vector<int> p(l+1);
    for(int i=1; i<=l; i++)
        cin>>p[i];
    int b; cin>>b;
    int x; cin>>x;
    int ans=0;
    int ind=1,marad=k;
    while(ind<l)
    {
        int cs=p[ind],kov=p[ind+1];
        if(dist[cs][kov]+(ind+1==l?0:dist[kov][x])<=marad)
        {
            ans+=dist[cs][kov];
            marad-=dist[cs][kov];
            ind++;
        }
        else
        {
            ans+=dist[cs][x];
            if(marad<dist[cs][x])
            {
                cout<<"-1\n";
                return 0;
            }
            marad=k;
            ind++;
            if(dist[x][kov]>k)
            {
                cout<<"-1\n";
                return 0;
            }
            marad-=dist[x][kov];
            ans+=dist[x][kov];
        }
    }
    cout<<ans<<"\n";
}