diff --git a/exercises/ex10/ex10b.py b/exercises/ex10/ex10b.py
index 379bd1a..fa16b9b 100644
--- a/exercises/ex10/ex10b.py
+++ b/exercises/ex10/ex10b.py
@@ -29,10 +29,10 @@ for path in list(root.glob("**/*")):
 
 print(f"Mostrando archivos >= a {size_max}MB:")
 # print(f"Eliminando archivos >= a {size_max}MB:")
-big_files = sorted(big_files, reverse=True, key=lambda f: f['size'])
+big_files = sorted(big_files, reverse=True, key=lambda f: f["size"])
 biggest = str(format(big_files[0]["size"], ","))
 for file in big_files:
     size = str(format(file["size"], ","))
     space = " " * (len(biggest) - len(size))
     print(f"[{space}{size}] {file['path']}")
-    # file["path"].unlink()  # PELIGRO: si se descomenta eliminará el archivo
+    # file["path"].unlink()  # PELIGRO: eliminará el archivo
diff --git a/exercises/ex10/ex10c.py b/exercises/ex10/ex10c.py
index 6e12607..2248961 100644
--- a/exercises/ex10/ex10c.py
+++ b/exercises/ex10/ex10c.py
@@ -2,3 +2,49 @@
 Project: Filling in the Gaps
 Page 248
 """
+
+import re
+import sys
+import argparse
+from pathlib import Path
+
+parser = argparse.ArgumentParser(description="Renumeración de archivos")
+parser.add_argument("-p", "--pattern", type=str, default="*.*")
+parser.add_argument("-i", "--input", type=Path, default=Path.cwd())
+parser.add_argument("--add-gap", type=int, default=0)
+args = parser.parse_args()
+files = []
+
+if not args.input.exists():
+    print("ERROR: el input no existe")
+    sys.exit(1)
+
+for path in list(args.input.glob(args.pattern)):
+    try:
+        index = int(re.sub(r"^\D+", "", path.stem))
+    except Exception:
+        index = 0
+    files.append({"index": index, "path": path})
+
+if len(files) == 0:
+    print(f"No se encontraron archivo con el patrón '{args.pattern}'")
+    sys.exit()
+
+files = sorted(files, key=lambda f: f["index"])
+biggest = str(files[-1]["index"])
+curr_index = 1
+for file in files:
+    if args.add_gap == curr_index:
+        curr_index += 1
+    num = str(curr_index)
+    zeros = "0" * (len(biggest) - len(num))
+    index = f"{zeros}{num}"
+    curr_index += 1
+    if re.search(r"\d+", file["path"].stem):
+        parts = re.split(r"\d+", file["path"].stem)
+        file_name = parts[0] + index + "".join(parts[1:])
+    else:
+        file_name = file["path"].stem + index
+    new_path = file["path"].parent / f"{file_name}{file['path'].suffix}"
+    print(f"{file['path']} => {new_path}")
+    # file["path"].rename(new_path)  # PELIGRO: renombrará el archivo
diff --git a/exercises/ex10/test.txt b/exercises/ex10/test.txt
new file mode 100644
index 0000000..e69de29
diff --git a/exercises/ex10/test004.txt b/exercises/ex10/test004.txt
new file mode 100644
index 0000000..e69de29
diff --git a/exercises/ex10/test02.txt b/exercises/ex10/test02.txt
new file mode 100644
index 0000000..e69de29
diff --git a/exercises/ex10/test1.txt b/exercises/ex10/test1.txt
new file mode 100644
index 0000000..e69de29
diff --git a/exercises/ex10/test10.txt b/exercises/ex10/test10.txt
new file mode 100644
index 0000000..e69de29