diff --git a/Top150Interview/20_Valid_Parenthesis.py b/Top150Interview/20_Valid_Parenthesis.py
index e488cc8..54f8d9f 100644
--- a/Top150Interview/20_Valid_Parenthesis.py
+++ b/Top150Interview/20_Valid_Parenthesis.py
@@ -1,6 +1,25 @@
-def isValid(self, s):
+def isValid(s):
     """
     :type s: str
     :rtype: bool
     """
-    
\ No newline at end of file
+    pervious = ""
+    openBracket = ['(', '{', '[']
+    bracketPairs = ['()', '{}', '[]']
+    pairs = None
+
+    for x in s:
+        if x in openBracket:
+            previous = x
+        else:
+            # print(previous+x)
+            if (previous+x) in bracketPairs:
+                pairs = True
+            else:
+                return False
+    return pairs
+
+print(isValid("()"))
+print(isValid("()[]{}"))
+print(isValid("(]"))
+print(isValid("([)]"))
\ No newline at end of file