Faster checked arithmetic (with outer loop)

CheckedOuter

using System;
using System.Diagnostics;

class Program
{
	static void Main(string[] args)
	{
		var s = new Stopwatch();
		s.Start();
		var outerSum = 0;
		for (int outerIndex = 0; outerIndex < 20; ++outerIndex) {
			int a = 0;
			for (int i = 0; i < 100000000; i += 3) {
				if (i == 1000)
					i *= 2;
				if (i % 35 == 0)
					++a;
			}
			outerSum += a;
		}
		s.Stop();
		Console.WriteLine(s.ElapsedMilliseconds);
		Console.WriteLine(outerSum);
	}
}