I keep getting this error, and I'm not understanding why? StudentsCode.cs(23,0): error CS1525: Unexpected symbol `{'

The problem is that you provide a condition for your else statement. An else statement runs automatically if the above if/else if statements do not run, therefore it does not accept any condition on its own.

You can fix the issue by either changing it into an else if statement which does accept conditions, or by simply removing the condition all together since its not actually needed. The if/else if conditions above it already cover less than 21 degrees and 21 to 22 degrees so an else statement would only include values other than those. Like this:

string input = Console.ReadLine();
int temperature = int.Parse(input);

if(temperature < 21)
{
    System.Console.WriteLine("Too Cold!");
}
else if(temperature == 21)
{
    System.Console.WriteLine("Just right.");
}
else if(temperature == 22)
{
     System.Console.WriteLine("Just right.");
}
else
{
    System.Console.WriteLine("Too hot!");
}

Also just as a bit of a tip, you don't need two else if statements to print "Just right." you can accomplish the task with just one by having the condition be <= 22. That way it will run for 21 but also for 22. Like this:

string input = Console.ReadLine();
int temperature = int.Parse(input);

if(temperature < 21)
{
    System.Console.WriteLine("Too Cold!");
}
else if(temperature <= 22)
{
     System.Console.WriteLine("Just right.");
}
else
{
    System.Console.WriteLine("Too hot!");
}