use proconio::{input, marker::Usize1};
use std::collections::VecDeque;

fn main() {
    input! {
        n: usize,
        m: usize,
        uv: [(Usize1, Usize1); m],
        l: usize,
        jk: [(Usize1, usize); l],
    }

    let mut graph = vec![vec![]; n];
    for (u, v) in uv {
        graph[u].push(v);
        graph[v].push(u);
    }
    let mut visited = vec![false; n];

    let mut queue = VecDeque::new();
    for (j, k) in jk {
        visited[j] = true;
        if k >= 1 {
            queue.push_back((j, k));
        }
    }

    while let Some((pos, count)) = queue.pop_front() {
        for &next in &graph[pos] {
            if visited[next] {
                continue;
            }

            visited[next] = true;
            if count == 1 {
                continue;
            }
            queue.push_back((next, count - 1));
        }
    }

    if visited[0] {
        println!("No");
        return;
    }

    queue.push_back((0, 0));
    while let Some((pos, count)) = queue.pop_front() {
        for &next in &graph[pos] {
            if visited[next] {
                continue;
            }

            if next == n - 1 {
                println!("Yes");
                println!("{}", count + 1);
                return;
            }
            visited[next] = true;
            queue.push_back((next, count + 1));
        }
    }
    println!("No");
}