# C#: Project Euler Solution to Problem 47

http://projecteuler.net/problem=47

The first two consecutive numbers to have two distinct prime factors are:

14 = 2 x 7
15 = 3 x 5

Find the first four consecutive integers to have four distinct primes factors. What is the first of these numbers?

```static void Main(string[] args) { LinkedList<int> threefactors = new LinkedList<int>(); int n = 0; while (true) { n++; int factcount = 0; for (int i = 1; i <= n; i++) { if (n % i == 0 && isPrime(i)) factcount++; } if (factcount == 4) { threefactors.AddLast(n); int lastn = (n - 1); int lastn2 = (n - 2); int lastn3 = (n - 3); if (threefactors.Contains(lastn) && threefactors.Contains(lastn2) && threefactors.Contains(lastn3)) { Console.WriteLine(n); Console.WriteLine(lastn); Console.WriteLine(lastn2); Console.WriteLine(lastn3); break; } } } } public static bool isPrime(int n) { if (n == 1) return false; if (n == 2) return true; for (int i = 2; i < n; ++i) { if ((n % i) == 0) return false; } return true; }```