diff --git a/09/09.py b/09/09.py
new file mode 100644
index 0000000..758b302
--- /dev/null
+++ b/09/09.py
@@ -0,0 +1,67 @@
+
+
+
+
+data = open("input.txt").read().strip()
+def f(data):
+    data = list(map(int, data))
+
+    nl = 1
+    nr = len(data)//2
+    l = data[0]
+    s = data[0]*0
+    i = 1
+    j = -1
+    while i<len(data)+j:
+        if data[i]<=data[j]:
+            s += sum(range(l, l+data[i]))*nr
+            l += data[i]
+            data[j] -= data[i]
+            i += 1
+            s += sum(range(l, l+data[i]))*nl
+            l += data[i]
+            nl += 1
+            i += 1
+        else:
+            s += sum(range(l, l+data[j]))*nr
+            l += data[j]
+            nr -= 1
+            data[i] -= data[j]
+            j -= 2
+    return s
+
+print(f(data))
+
+def fat(data):
+    "FAT - File Allocation Table"
+    data = list(map(int, data))
+
+    files = []
+    emptys = []
+    l = 0
+    n = 0
+    for i in range(len(data)):
+        if i%2==0:
+            files.append((n, l, l+data[i]))
+            n += 1
+        else:
+            emptys.append((l, l+data[i]))
+        l += data[i]
+    return files, emptys
+
+def f2(files, emptys):
+    for i in reversed(range(len(files))):
+        n, s, e = files[i]
+        j = 0
+        l, r = emptys[0]
+        while not (j==len(emptys) or e-s<=r-l or s<l):
+            j += 1
+            l, r = emptys[j]
+        if e-s<=r-l:
+            files[i] = (n, l, l+e-s)
+            emptys[j] = (l+e-s, r)
+    return sum(n*(sum(range(s, e))) for n, s, e in files)
+
+assert f2(*fat("2333133121414131402"))==2858
+
+print(f2(*fat(data)))