how do i check if a string contains only words and space
ive got an if statement that needs to check if a string contains only letters or spaces, online i can only find how to check for only letters which then flags the spaces as not letters

public static void ContainsOnlyLetters(this string input)
{
int count5 = 0;
foreach (char c in input)
{
if (!Char.IsLetterOrDigit(c))
count5++;
else if (!Char.IsWhiteSpace(c))
count5++;
}
if (count5 != input.Length)
{
Console.WriteLine("Invalid restaurant name in file, please select a valid file.");
LoadFoodMenu();
}
else
{
return;
}
}