static void Main(string[] args)
{
PrimeNumber PNumber = new PrimeNumber();
long sum = 0;
int limit = 2000000;
for (int i = 2; i <= limit; i++)
{
if (PNumber.isPrime(i))
{
sum += i;
}
}
Console.WriteLine("Sum of numbers below 2000000 is " + sum);
Console.ReadLine();
}