$(55\%)$ Write a C# program that

$($a$)(10\%)$ Prompts for an integer $n($that you type from keyboard$)$

$($b$)(30\%)$ Display the following: $($like in Q$1,$ except $10$ is replaced by $n)$

Sum of $1+2+3+=+n$ is $1$ in iteration $1_{?}$

Sum of $1+2+3+=+n$ is $3$ in iteration $\frac{1}{2}$

Sum of $1+2+3+$dots$+n$ is $6$ in iteration $3_{?}$

Until the last iteration

Sum of $1+2+3+=+n$ is in iteration n

Note that if $n=10,$ the output is the same as Q $1.$

If $n=20,$ your output will look like

Sum of $1+2+3+=+20$ is $1$ in iteration $\frac{1}{2}$

Sum of $1+2+3+=+20$ is $3$ in iteration $\frac{1}{2}$

Sum of $1+2+3+=+20$ is $6$ in iteration $3$

Sum of $1+2+3+$dots$+20$ is $190$ in iteration ${19}_{?}$

Sum of $1+2+3+=+20$ is $210$ in iteration $20($from the formula, we know $1+2+=+n=n\frac{n+1}{2},$ so with $n=$

$20,$ sum $=210$

$($c$)(15\%)$ Test and show your program's output for three different n :

$n=10,n=20,$ and $n=$ an integer between $11$ and $19$ picked by you.

Note. Your code of course wark for any $n$ such as $n=100,n=200,$ etc. but refrain from doing that since too

many lines of outputs will be generated.