diff --git a/examples/get_sign.c b/examples/get_sign.c
index 0e5cf99d0193dab34b8ed2a1fb152557f8e5a4f2..1c7353c762afb8694d34d2247a6e7cc20c817d83 100644
--- a/examples/get_sign.c
+++ b/examples/get_sign.c
@@ -9,8 +9,11 @@ int get_sign(int x)
 {
     if (x == 0)
         return 0;
+    if (x == 1)
+        return 0;
+
 
-    if (x < 0)
+    if (x < 2)
         return -1;
     else
         return 1;
@@ -193,7 +196,8 @@ int main()
 // `klee_make_symbolic(&a, sizeof(a), "a");`
 // works when you run `klee` to generate test cases:
 //
-// [your answer here]
+// [It takes the address of variable a and treat is as symbolic. 
+// It will mark the memory locattion of a as symbolic.]
 // (hint, mark memory region as symbolic)
 //
 // Explain in your own words how