diff --git a/01_phase_rust_src/sv/src/parser.rs b/01_phase_rust_src/sv/src/parser.rs
index aa2a608..716011b 100644
--- a/01_phase_rust_src/sv/src/parser.rs
+++ b/01_phase_rust_src/sv/src/parser.rs
@@ -90,12 +90,12 @@ pub fn parse_args_1(arg: &String) -> String{
 
 
 pub fn parse_args_2(arg: &String) -> String{
-    let possible: Vec<&str> = vec!["start", "stop", "reload", "restart", "shutdown", "force-stop", "force-reload", "force-restart", "force-shutdown", "try-restart"];
-    let cpossible: Vec<char> = vec!['s', 'u', 'd', 'o', 'p', 'c', 'h', 'a', 'i', 'q', '1', '2', 't', 'k'];
+    const POSSIBLE: &'static [&'static str] = &["start", "stop", "reload", "restart", "shutdown", "force-stop", "force-reload", "force-restart", "force-shutdown", "try-restart"];
+    const CPOSSIBLE: &'static [char] = &['s', 'u', 'd', 'o', 'p', 'c', 'h', 'a', 'i', 'q', '1', '2', 't', 'k'];
 
 
         
-    for var in possible.iter() {
+    for var in POSSIBLE.iter() {
         if arg == var {
             return var.to_string()
         }
@@ -105,7 +105,7 @@ pub fn parse_args_2(arg: &String) -> String{
     let ch1 = arg.chars().next().unwrap();
 
 
-    for var in cpossible.iter() {
+    for var in CPOSSIBLE.iter() {
         if ch1 == *var {
             return ch1.to_string()
         }