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Note: The code below applies to version 0.3 of Microsoft Axum. If you are not using this version of Axum, then your code may differ from that shown here.

I have just solved Problem 1 of Project Euler using Microsoft Axum. The problem statement is as follows:

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all the multiples of 3 or 5 below 1000.

My Axum-based solution is as follows:

`namespace EulerProjectProblem1{    // http://projecteuler.net/index.php?section=problems&id=1    //    // If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9.    // The sum of these multiples is 23.    // Find the sum of all the multiples of 3 or 5 below 1000.        channel SumOfMultiples    {        input int Multiple1;        input int Multiple2;        input int UpperBound;        output int Sum;    }        agent SumOfMultiplesAgent : channel SumOfMultiples    {        public SumOfMultiplesAgent()        {            int Multiple1 = receive(PrimaryChannel::Multiple1);            int Multiple2 = receive(PrimaryChannel::Multiple2);            int UpperBound = receive(PrimaryChannel::UpperBound);            int Sum = 0;                        for(int Index = 1; Index < UpperBound; Index++)            {                if((Index % Multiple1 == 0) || (Index % Multiple2 == 0))                Sum += Index;            }            PrimaryChannel::Sum <-- Sum;        }    }        agent MainAgent : channel Microsoft.Axum.Application    {        public MainAgent()        {            var SumOfMultiples = SumOfMultiplesAgent.CreateInNewDomain();            SumOfMultiples::Multiple1 <-- 3;            SumOfMultiples::Multiple2 <-- 5;            SumOfMultiples::UpperBound <-- 1000;            var Sum = receive(SumOfMultiples::Sum);            System.Console.WriteLine(Sum);            System.Console.ReadLine();            PrimaryChannel::ExitCode <-- 0;        }    }}`

Let’s take a look at the various parts of the code.

I begin by setting up a channel called SumOfMultiples that accepts three inputs and one output. The first two of the three inputs will represent the two possible multiples, which are three and five in this case. The third input will represent the upper bound of the problem scope, which is 1000 in this case. The lone output of the channel represents the sum of all of the matching multiples:

`channel SumOfMultiples{    input int Multiple1;    input int Multiple2;    input int UpperBound;    output int Sum;}`

I then set up an agent that uses the channel. The agent, called SumOfMultiplesAgent, received the three inputs from the channel sent to the agent, stores the results in local variables, and performs the for loop that iterates from 1 to the received upper bound. The agent keeps track of the sum in a local variable and stores the sum in the output portion of the channel:

`agent SumOfMultiplesAgent : channel SumOfMultiples{    public SumOfMultiplesAgent()    {        int Multiple1 = receive(PrimaryChannel::Multiple1);        int Multiple2 = receive(PrimaryChannel::Multiple2);        int UpperBound = receive(PrimaryChannel::UpperBound);        int Sum = 0;                for(int Index = 1; Index < UpperBound; Index++)        {            if((Index % Multiple1 == 0) || (Index % Multiple2 == 0))            Sum += Index;        }        PrimaryChannel::Sum <-- Sum;    }}`

The application’s main agent, therefore, simply creates a new SumOfMultiplesAgent in a new domain, prepares the channel with the inputs that we need, and then receives the Sum from the output portion of the channel:

`agent MainAgent : channel Microsoft.Axum.Application{    public MainAgent()    {        var SumOfMultiples = SumOfMultiplesAgent.CreateInNewDomain();        SumOfMultiples::Multiple1 <-- 3;        SumOfMultiples::Multiple2 <-- 5;        SumOfMultiples::UpperBound <-- 1000;        var Sum = receive(SumOfMultiples::Sum);        System.Console.WriteLine(Sum);        System.Console.ReadLine();        PrimaryChannel::ExitCode <-- 0;    }}`

The result of the calculation (which, by the way, is 233,168) is sent to the console using good ol’ Console.WriteLine().