diff --git a/adventofcode/aoc.py b/adventofcode/aoc.py
index 7950359..1149618 100644
--- a/adventofcode/aoc.py
+++ b/adventofcode/aoc.py
@@ -1,35 +1,68 @@
 import argparse
-from adventofcode.helper import run, get_input_file
+from pathlib import Path
+from adventofcode.helper import run, get_input_file, get_auth
+
+
+TEMPLATE = """#!/usr/bin/env python3
+def main(inp):
+    for l in inp:
+        print(l)
+
+
+if __name__ == '__main__':
+    import fileinput
+    lines = [x.rstrip() for x in fileinput.input()]
+    main(lines)
+"""
 
 
 def main():
     parser = argparse.ArgumentParser(description="Advent of Code CLI")
-    subparsers = parser.add_subparsers(dest='command')
+    subparsers = parser.add_subparsers(dest="command")
 
-    # Sous-commande init
-    init_parser = subparsers.add_parser('init', help='Init an aoc day')
-    init_parser.add_argument('year', type=int)
-    init_parser.add_argument('day', type=int)
+    init_parser = subparsers.add_parser("init", help="Init an aoc day")
+    init_parser.add_argument("year", type=int)
+    init_parser.add_argument("day", type=int)
 
-    # Sous-commande run
-    run_parser = subparsers.add_parser('run', help='Run an aoc day')
-    run_parser.add_argument('year', type=int)
-    run_parser.add_argument('day', type=int, nargs='?', default=None)
+    run_parser = subparsers.add_parser("run", help="Run an aoc day")
+    run_parser.add_argument("year", type=int)
+    run_parser.add_argument("day", type=int, nargs="?", default=None)
 
     args = parser.parse_args()
 
-    if args.command == 'init':
+    if args.command == "init":
         handle_init(args.year, args.day)
-    elif args.command == 'run':
+    elif args.command == "run":
         handle_run(args.year, args.day)
     else:
         parser.print_help()
 
 
 def handle_init(year, day):
-    # TODO initialize directory if needed, download input file and create
-    # dayX.py from a template
-    raise NotImplementedError("init")
+    if not 1 <= day <= 25:
+        print(f"Invalid day: {day}. Must be between 1 and 25.")
+        return
+
+    root = Path(__file__).parent
+    day_dir = root / str(year) / f"day{day}"
+    day_dir.mkdir(parents=True, exist_ok=True)
+
+    script_path = day_dir / f"day{day}.py"
+    if not script_path.exists():
+        script_path.write_text(TEMPLATE)
+        print(f"Created {script_path}")
+    else:
+        print(f"{script_path} already exists")
+
+    input_path = day_dir / "input.txt"
+    if not input_path.exists():
+        try:
+            get_auth()
+            res = get_input_file(year, day)
+            input_path.write_bytes(res.read())
+            print(f"Downloaded {input_path}")
+        except Exception as e:
+            print(f"Could not download input: {e}", file=__import__("sys").stderr)
 
 
 def handle_run(year, day):
@@ -38,4 +71,3 @@ def handle_run(year, day):
 
 if __name__ == "__main__":
     main()
-