diff --git a/Basic-Graphs/cs412_islands_a.py b/Basic-Graphs/cs412_islands_a.py
index 50a5050..63186dc 100644
--- a/Basic-Graphs/cs412_islands_a.py
+++ b/Basic-Graphs/cs412_islands_a.py
@@ -8,38 +8,30 @@ Honor Code and Acknowledgments:
        Comments here on your code and submission.
 """
 
-import numpy as np
 
-type LandGrid = np.ndarray[tuple[int, int], np.dtype[np.bool]]
-
-
-def explore_island(grid: LandGrid, start: tuple[int, int]) -> int:
-    num_rows, num_cols = grid.shape
+def explore_island(grid: list[list[int]], start: tuple[int, int]) -> int:
+    num_rows: int = len(grid)
+    num_cols: int = len(grid[0])
     size: int = 0
 
     def recurse(coord: tuple[int, int]):
         x, y = coord
 
-        if not grid[y, x]:
+        if grid[y][x] == 0:
             return
 
         nonlocal size
         size += 1
-        grid[y, x] = False
-
-        neighbors: list[tuple[int, int]] = []
+        grid[y][x] = 0
 
         if y > 0:
-            neighbors.append((x, y - 1))
+            recurse((x, y - 1))
         if y < num_rows - 1:
-            neighbors.append((x, y + 1))
+            recurse((x, y + 1))
         if x > 0:
-            neighbors.append((x - 1, y))
+            recurse((x - 1, y))
         if x < num_cols - 1:
-            neighbors.append((x + 1, y))
-
-        for neighbor in neighbors:
-            recurse(neighbor)
+            recurse((x + 1, y))
 
     recurse(start)
 
@@ -51,16 +43,16 @@ def explore_island(grid: LandGrid, start: tuple[int, int]) -> int:
 def main():
     n: int = int(input())
 
-    raw_matrix: list[list[int]] = [list(map(int, input().split())) for _ in range(0, n)]
+    land_grid: list[list[int]] = [list(map(int, input().split())) for _ in range(0, n)]
 
-    land_grid: LandGrid = np.array(raw_matrix, dtype=bool)
-    num_rows, num_cols = land_grid.shape
+    num_rows: int = n
+    num_cols: int = len(land_grid[0])
 
     largest_island: int = -1
 
     for y in range(0, num_rows):
         for x in range(0, num_cols):
-            if not land_grid[y, x]:
+            if land_grid[y][x] == 0:
                 continue
 
             island_size: int = explore_island(land_grid, (x, y))