@strings = ("notalot",
            "england,rugby" ,
            "chicken,egg,duck,feet" ,

            ",southampton" ,
            "bristol," ,
            "iran, canada,france" ,
            "" ,
);

for (@strings) {
    print "$_\n" if /^[a-zA-Z]([a-zA-Z]+|,(?!,|$))*$/;
}