diff --git a/class/LogicUtils.php b/class/LogicUtils.php
index 068adf5..8ac7614 100644
--- a/class/LogicUtils.php
+++ b/class/LogicUtils.php
@@ -49,7 +49,7 @@ class LogicUtils
         } else {
             $numa_str = self::extend($numa_str, $base, $digits, false);
             if (($rep === "c") && ($numa_str[0] >= ($base / 2))) {
-                $numa_str = str_pad($numa_str, 1, "0", STR_PAD_LEFT);
+                $numa_str = "0" . $numa_str;
             }
         }
         return $numa_str;