static void Main(string[] args)
{
ILineReader reader;
if (args.Length > 0)
{
reader = new FileLineReader(args[0]);
}
else
{
reader = new ConsoleLineReader();
}
var input = reader.ReadLine().Split(' ');
var N = int.Parse(input[0]);
var I = int.Parse(input[1]);
var pic = new ParticipantsInCountries();
while (I > 0)
{
I--;
input = reader.ReadLine().Split(' ');
var p1 = int.Parse(input[0]);
var p2 = int.Parse(input[1]);
pic.Add(p1, p2);
}
pic.Normalize();
var total = pic.countries.Sum(p => p.members.Count);
var singleGroups = N - total;
ComboGenerator cg = new ComboGenerator(pic.countries.Count, 2);
long sum = 0;
var combo = cg.Next();
while (combo != null)
{
sum += pic.countries[(int)combo[1] - 1].Count * pic.countries[(int)combo[2] - 1].Count;
combo = cg.Next();
}
var singleCombo = (long)(FactByFact(singleGroups, singleGroups - 2) / Fact(2));
var comboIntoCountry = pic.countries.Sum(p => p.members.Count * singleGroups);
sum += singleCombo + comboIntoCountry;
Console.WriteLine(sum);
}
static void Main(string[] args)
{
ComboGenerator cgn = new ComboGenerator(20, 1);
var arr = cgn.Next();
while (arr != null)
{
PrintArray(arr);
arr = cgn.Next();
}
//CobinationGenerator c = new CobinationGenerator();
//c.GenerateCombo(9, 8);
Console.ReadLine();
}
