use proconio::input;
use std::collections::{HashSet, VecDeque};
fn main() {
    input! {
      n: usize,
      m: usize,
    }
    let mut graph = vec![HashSet::<usize>::new(); n+1];
    for _ in 0..m {
        input!{
            u: usize,
            v: usize
        }
        graph[u].insert(v);
        graph[v].insert(u);
    }
    input!{
        k: usize
    }
    let mut iwai = vec![false; n+1];
    for _ in 0..k {
        input!{
            a: usize
        }
        iwai[a] = true;
    } 
    let mut q = VecDeque::new();
    q.push_back((1,0,0));
    let mut visited = vec![vec![false; n+1]; 5];
    while let Some(state) = q.pop_front() {
        let (pos, encount, depth) = state;
        if pos == n { println!("{}", depth); return;}
        for v in &graph[pos]{
            let mut nenc=encount;
            if iwai[pos] { nenc += 1;} else { nenc = 0; }
            
            if nenc == 5 {continue;}
            if visited[nenc][*v] {continue;}
            visited[nenc][*v] = true;
            q.push_back((*v,nenc,depth+1));
        }
    }
    println!("-1");
}