diff --git a/src/main.rs b/src/main.rs
index 84d0c13..eaa12a2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -39,31 +39,27 @@ fn main() {
     }
   }
   let mut verbose = false;
-  // let mut expression_opt = None;
+  let mut expression_opt = None;
   for arg in get_args() {
     match arg.as_str() {
       "-v" | "--verbose" => verbose = true,
       _ => {
-        // if expression_opt == None {
-        //   expression_opt = Some(arg);
-        // } else {
-        //   eprintln!("Unexpected argument: {}", arg);
-        //   exit(1);
-        // }
+        if expression_opt == None {
+          expression_opt = Some(arg);
+        } else {
+          eprintln!("Unexpected argument: {}", arg);
+          exit(1);
+        }
       }
     }
   }
-  // let expression = match expression_opt {
-  //   Some(expression) => expression,
-  //   None => {
-  //     print_help();
-  //     exit(0);
-  //   },
-  // };
-  let mut expression = "0 watt".to_string();
-  for _ in 0..10 {
-    expression.push_str(" plus 1watt");
-  }
+  let expression = match expression_opt {
+    Some(expression) => expression,
+    None => {
+      print_help();
+      exit(0);
+    },
+  };
   match eval(&expression, true, Unit::Celsius, verbose) {
     Ok(answer) => {
       if !verbose {