using System;

public class Program

{

    public static void Main()

    {

        int target = 9;

        var r = new Random();

        int iterations = 100000;

        int cnt = 0;

        for(int i=0; i < iterations; i++)

        {

            // 3d6 pick highest

            var a = r.Next(1,7);

            var b = r.Next(1,7);

            var c= r.Next(1,7);

            var sum = a+b+c;

            var min = Math.Min(Math.Min(a,b),c);

            //3d6

            var d1 =  (sum - min)>=target ? 1:0;

            // normal

            //var d1 = (r.Next(1,7)+r.Next(1,7))>=target ? 1:0;

            var d2 = (r.Next(1,7)+r.Next(1,7))>=target? 1:0;

            //var d3 = (r.Next(1,7)+r.Next(1,7))>=target? 1:0;

            // calculate if sucesss

            if((d1 + d2) >= 2) {cnt++;}

        }

            Console.WriteLine((cnt/1.0)/(iterations/1.0));

    }

}