using System;

public static class Lab$4\_1$

$\{$

public static void Main$()$

$\{$

int value $=0,$ sum $=0,$ count $=0$;

double average $=0\mathrm{.}0$;

Console.Clear$()$;

$//$ Read initial value $($seed the loop$)$

Console.Write$("$Enter a positive integer $(-1$ to stop$)$: $")$;

value $=$ Convert.ToInt$32($Console$.$ReadLine$())$;

$//$ if the inputted value is not the sentinel value, process it

while $($value $>=0)$

$\{$

$//$ Calculate the running total

sum $+=$ value; $//$ same as sum $=$ sum $+$ value;

$//$ Keep track of the number of inputted values

count$++$; $//$ same as count $=$ count $+1$;

$//$ Read next value

Console.Write$("$Enter a positive integer $(-1$ to stop$)$: $")$;

value $=$ Convert.ToInt$32($Console$.$ReadLine$())$;

$\}$

$//$ Calculate average $($only if the user inputted any numbers$)$

if $($count $>0)$

average $=$ sum $/($double$)$ count;

else

average $=0$;

$//$ Print results

Console.WriteLine$("$sum $=\{0\},$ count $=\{1\}",$ sum, count$)$;

Console.WriteLine$("$average $=\{0$:F$2\}",$ average$)$;

$\}$

$\}$