Alphanumeric validation check using Regex

String value = "Pankaj Singh 1952";
Pattern pattern = Pattern.compile("[a-zA-Z][a-zA-Z0-9 ]*");
Matcher matcher = pattern.matcher(value);
boolean flag = matcher.matches();

if (flag) {
System.out.println("correct value");
} else {
System.out.println("incorrect value");
}