diff --git a/2021/day10/10.py b/2021/day10/10.py
new file mode 100644
index 0000000..27a63e4
--- /dev/null
+++ b/2021/day10/10.py
@@ -0,0 +1,22 @@
+lines = open("input.txt", 'r').read().splitlines()
+
+
+di = {
+    ')': ('(', 3),
+    ']': ('[', 57),
+    '}': ('{', 1197),
+    '>': ('<', 25137)
+}
+score = 0
+
+for l in lines:
+    stack = []
+    for c in l:
+        if c == '(' or c == '[' or c == '{' or c == '<':
+            stack.append(c)
+        if c == ')' or c == ']' or c == '}' or c == '>':
+            if stack.pop() != di.get(c)[0]:
+                score += di.get(c)[1]
+                break
+
+print(score)
\ No newline at end of file
diff --git a/2021/day9/9a.py b/2021/day9/9.py
similarity index 100%
rename from 2021/day9/9a.py
rename to 2021/day9/9.py
diff --git a/README.md b/README.md
index 28a344d..0c8d07a 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 my solutions for the [Advent of Code](https://adventofcode.com/)
 
 in progress:\
-2021 (python)\
+2021 (python)
 
 planned:\
 2022 (rust)\