public static void main()
{
String s = Console.ReadLine();
int len = s.length();
Char startletter = s[0];
Char endletter = s[len-1];
string midletter = ‘’;
if(len % 2 ==0)
midletter = s[len/2] + s[(len/2) +1]
else
midletter = s[len/2];
Console.WriteLine(startletter + midletter + endletter);
}
Here the logic is that, startletter is obtained using the index ‘0’, the last letter is obtained by calculating the “length of the string” and subtract 1 to get the “last index” of the given string.
Middle letter is calculated by first finding whether the given string length is “odd or even” and based on that index(es) are identified.