diff --git a/src/wallet/wallet_impl.rs b/src/wallet/wallet_impl.rs
index b09f993..39ef366 100644
--- a/src/wallet/wallet_impl.rs
+++ b/src/wallet/wallet_impl.rs
@@ -110,19 +110,13 @@ impl Wallet {
         let key_str_0: &str = &self.master_key;
         let key0 = BigInt::parse_bytes(&key_str_0.as_bytes(), 16).unwrap();
         let kp0: (usize, BigInt) = (1, key0);
-        let i: usize;
-        let key_str_1: &str;
-        if let Some(val) = &self.second_key {
-            i = 2;
-            key_str_1 = val;
-        } else if let Some(val) = &self.backup_key {
-            i = 3;
-            key_str_1 = val;
-        } else {
-            println!("error");
-            i = 2;
-            key_str_1 = "";
-        }
+        let (i, key_str_1) = match (&self.second_key, &self.backup_key) {
+            (Some(val), _) => (2, val),
+            (_, Some(val)) => (3, val),
+            _ => {
+                panic!("error generate key")
+            }
+        };
         let key1 = BigInt::parse_bytes(&key_str_1.as_bytes(), 16).unwrap();
         let kp1 = (i, key1);
         let _tmp = vec![kp0, kp1];
@@ -172,6 +166,7 @@ impl Wallet {
         write!(s, "{:02x}", rv).unwrap();
         Ok(s)
     }
+    
     pub fn sign_for_tran<S>(&self, msg: S) -> Result<(String, i32)>
     where
         S: AsRef<[u8]>,