#nullable enable

#region
var (_input, _iter) = (Array.Empty<string>(), 0);
T I<T>() where T : IParsable<T>
{
    while (_iter >= _input.Length) (_input, _iter) = (Console.ReadLine()!.Trim().Split(' '), 0);
    return T.Parse(_input[_iter++], null);
}
#endregion

static T[] Range<T>(int n, Func<T> F) => Enumerable.Range(0, n).Select(_ => F()).ToArray();

var n = I<int>();
var m = I<int>();
var edges = Range(m, () => (I<int>() - 1, I<int>() - 1));
var l = I<int>();
var scopes = Range(l, () => (I<int>() - 1, I<int>()));

var g = new StaticGraph(edges, n, false);
var supervised = new bool[n];
var tmpbn = new bool[n];
foreach (var (j, k) in scopes)
{
    var q1 = new Queue<int>();
    q1.Enqueue(j);
    tmpbn[j] = true;
    var q2 = new Queue<int>();
    var h = new List<int>(){ j };
    for (var _lp = 0; _lp < k; _lp++)
    {
        if (q1.Count == 0) break;
        while (q1.Count > 0)
        {
            var v = q1.Dequeue();
            var adjz = g.Adjacencies(v);
            foreach (var (next, _) in adjz)
            {
                if (tmpbn[next]) continue;
                tmpbn[next] = true;
                q2.Enqueue(next);
                h.Add(next);
            }
        }
        (q1, q2) = (q2, q1);
    }
    foreach (var v in h)
    {
        supervised[v] = true;
        tmpbn[v] = false;
    }
}
var dists = new int[n].AsSpan();
var max = int.MaxValue / 2;
dists.Fill(max);
var q = new Queue<int>();
if (!supervised[0])
{
    q.Enqueue(0);
    dists[0] = 0;
}
while (q.Count > 0)
{
    var v = q.Dequeue();
    var nd = dists[v] + 1;
    var adjz = g.Adjacencies(v);
    foreach (var (next, _) in adjz)
    {
        if (supervised[next] || dists[next] <= nd) continue;
        dists[next] = nd;
        q.Enqueue(next);
    }
}
var ans = dists[n - 1];
if (ans >= max) Console.WriteLine("No");
else
{
    Console.WriteLine("Yes");
    Console.WriteLine(ans);
}

class StaticGraph
{
    public int N { get; }
    public bool Directed { get; }
    public ReadOnlySpan<(int next, int edgeIndex)> Adjacencies(int of) => _adjacencies.AsSpan()[_starts[of].._starts[of + 1]];
    public ReadOnlySpan<(int Ab, int Ad)> Edges => _edges;

    readonly (int Ab, int Ad)[] _edges;
    readonly (int, int)[] _adjacencies;
    readonly int[] _starts;

    public StaticGraph(IReadOnlyList<(int, int)> edges, int n, bool directed)
    {
        var ez = edges.ToArray();
        var el = ez.Length;
        var m = directed ? el : (el << 1);
        var starts = new int[n + 1];
        for (var i = 0; i < el; i++)
        {
            var (ab, ad) = ez[i];
            starts[ab + 1]++;
            if (!directed) starts[ad + 1]++;
        }
        for (var i = 0; i < n; i++) starts[i + 1] += starts[i];
        var adjacencies = new (int, int)[m];
        var counts = starts.AsSpan().ToArray();
        for (var i = 0; i < el; i++)
        {
            var (ab, ad) = ez[i];
            adjacencies[counts[ab]++] = (ad, i);
            if (!directed) adjacencies[counts[ad]++] = (ab, i);
        }
        N = n;
        Directed = directed;
        _adjacencies = adjacencies;
        _edges = ez;
        _starts = starts;
    }
}