Combine return and switch in C#

How can I combine return and switch case statements in C#?

I want something like

return switch (a)
{
    case 1: "lalala"
    case 2: "blalbla"
    case 3: "lolollo"
    default: "default" 
};

I know about this solution

switch (a)
{
    case 1: return "lalala";
    case 2: return "blalbla";
    case 3: return "lolollo";
    default: return "default";
}

But I want to only use the return operator.