Add tasks for all the new languages

Task/24-game/Sidef/24-game.sidef

@@ -0,0 +1,36 @@
+const digits  = (1..9 -> pick(4));
+const grammar = Regex.new(
+    '^ (?&exp) \z
+      (?(DEFINE)
+          (?<exp> ( (?&term) (?&op) (?&term) )+ )
+          (?<term> \( (?&exp) \) | [' + digits.join + '])
+          (?<op> [-+*/] )
+      )', 'x'
+);
+ 
+say "Here are your digits: #{digits.join(' ')}";
+ 
+loop {
+    var input = Sys.scanln("Expression: ");
+ 
+    var expr = input;
+    expr -= /\s+/g;    # remove all whitespace
+ 
+    input == 'q' && (
+        say "Goodbye.  Sorry you couldn't win.";
+        break;
+    );
+ 
+    var given_digits = digits.map{.to_s}.sort.join;
+    var entry_digits = input.scan(/\d/).sort.join;
+ 
+    if ((given_digits != entry_digits) || (expr !~ grammar)) {
+        say "That's not valid";
+        next;
+    }
+ 
+    given(var n = eval(input)) {
+        when (24) { say "You win!"; break }
+        default   { say "Sorry, your expression is #{n}, not 24" }
+    }
+}