diff --git a/linalg-practice.py b/linalg-practice.py
index 1f59dc8..72a9ff3 100644
--- a/linalg-practice.py
+++ b/linalg-practice.py
@@ -1,6 +1,7 @@
 import sympy as sp
 import time
 import random
+import readline
 
 def genmatrix(rowcol, intmax, dif) :
     # generate a random matrices