#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

var n = I<int>();
var m = I<int>();
var k = I<int>();
var iz = new int[n];
var oz = new int[n];
for (var i = 0; i < m; i++)
{
    var u = I<int>() - 1;
    var v = I<int>() - 1;
    oz[u]++;
    iz[v]++;
}
var l0 = new List<long>();
var ans = 0L;
for (var i = 0; i < n; i++)
{
    if (oz[i] == 0)
    {
        l0.Add(k - iz[i]);
        continue;
    }
    ans += Math.Max(0, k - iz[i]);
}
l0.Sort();
l0.Reverse();
if (n - 1 - k < l0.Count) ans += l0[(n - 1 - k)..].Sum();
Console.WriteLine(ans);