diff --git a/src/main.rs b/src/main.rs
index e7a11a9..30843e4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,29 @@
+use std::{fs, io::{self, BufRead, BufReader}};
+
 fn main() {
+
     println!("Hello, world!");
 }
+
+fn read_codes(code_file : &str) ->  io::Result<Vec<u32>> {
+    let file = fs::File::open(code_file)?;
+    let reader = BufReader::new(file);
+    let mut codes = Vec::new();
+    let mut line_count = 0;
+    for line in reader.lines() {
+        if let Ok(l) = line {
+            let r_str = l.as_str();
+            let code_vec : Vec<&str> = r_str.split(' ').collect();
+            if code_vec.len() == 2 {
+                let val1 : u32 = code_vec[0].parse().unwrap_or_default();
+                let val2 : u32 = code_vec[1].parse().unwrap_or_default();
+                codes.push(val1);
+                codes.push(val2);
+            } else {
+                println!("code error at line {}.", line_count);
+            }
+        }
+        line_count += 1;
+    }
+    Ok(codes)
+}