void Solve(StreamScanner ss, StreamWriter sw)
{
//---------------------------------
var N = ss.Next(int.Parse);
var A = ss.Next(int.Parse, N);
var dic = new Dictionary <int, int>();
foreach (var a in A)
{
if (dic.ContainsKey(a))
{
dic[a]++;
}
else
{
dic.Add(a, 1);
}
}
sw.WriteLine(dic.Sum(x => x.Value >= x.Key ? x.Value - x.Key : x.Value));
//---------------------------------
}