static void Main()
{
var n = int.Parse(Console.ReadLine());
var l = Read();
var set = new IndexedMultiSet <int>();
foreach (var x in l)
{
set.Add(x);
}
Array.Sort(l);
var r = 0;
for (int i = 0; i < n; i++)
{
for (int j = i + 1; j < n; j++)
{
r += set.GetLastIndex(x => x < l[i] + l[j]) - j;
}
}
Console.WriteLine(r);
}
static object Solve()
{
var(n, k) = Read2();
var s = Console.ReadLine();
var r = new List <char>();
var comp = Comparer2 <int> .Create(i => s[i], i => i);
var set = new IndexedMultiSet <int>(comp);
for (int i = 0; i < n - k; i++)
{
set.Add(i);
}
var t = -1;
for (int i = n - k; i < n; i++)
{
set.Add(i);
while (set.GetFirst() < t)
{
set.RemoveAt(0);
}
t = set.RemoveAt(0);
r.Add(s[t]);
}
return(string.Join("", r));
}
private void Start()
{
list = new List <int>(count);
set = new HashSet <int>(new IntComparer());
var comparer = new IntComparer();
indexedSet = new IndexedSet <int>(count, comparer);
multiSet = new IndexedMultiSet <int>(count, comparer);
data = new int[count];
}
static void Main()
{
var n = int.Parse(Console.ReadLine());
var ss = Array.ConvertAll(new bool[n], _ => Console.ReadLine());
var comp = Comparer2 <string> .Create(s => s.TrimStart('0').Length, s => s.TrimStart('0'), s => - s.Length);
var set = new IndexedMultiSet <string>(comp);
foreach (var s in ss)
{
set.Add(s);
}
Console.WriteLine(string.Join("\n", set));
}
static void Main()
{
var n = int.Parse(Console.ReadLine());
var set = new IndexedMultiSet <int>();
Console.SetOut(new System.IO.StreamWriter(Console.OpenStandardOutput())
{
AutoFlush = false
});
while (n-- > 0)
{
var q = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
if (q[0] == 0)
{
set.Add(q[1]);
Console.WriteLine(set.Count);
}
else if (q[0] == 1)
{
Console.WriteLine(set.GetCount(q[1]));
}
else if (q[0] == 2)
{
while (set.RemoveOne(q[1]))
{
;
}
}
else
{
foreach (var x in set.GetItems(x => x >= q[1], x => x <= q[2]))
{
Console.WriteLine(x);
}
}
}
Console.Out.Flush();
}
