diff --git a/sudoku.py b/sudoku.py
new file mode 100644
index 0000000..8ac5ada
--- /dev/null
+++ b/sudoku.py
@@ -0,0 +1,69 @@
+import time
+
+# Das Sudoku-Startfeld
+start = [
+    [0, 8, 0, 0, 2, 0, 5, 6, 0],
+    [0, 0, 0, 1, 0, 0, 0, 0, 7],
+    [0, 0, 0, 0, 0, 0, 0, 0, 0],
+    [0, 5, 0, 0, 9, 0, 4, 0, 8],
+    [0, 0, 7, 8, 0, 0, 0, 0, 3],
+    [0, 9, 0, 0, 1, 0, 0, 5, 0],
+    [2, 0, 4, 0, 0, 0, 8, 0, 0],
+    [0, 6, 0, 0, 8, 5, 0, 0, 0],
+    [0, 0, 0, 2, 0, 0, 1, 0, 0]
+]
+
+def isfine(feld, x, y):
+    # Doppelte Zahl in Zeile oder Spalte prüfen
+    for yi in range(9):
+        if yi != y and feld[x][yi] == feld[x][y]:
+            return False
+    for xi in range(9):
+        if xi != x and feld[xi][y] == feld[x][y]:
+            return False
+
+    # Neuner-Kästchen-Test
+    x1 = (x // 3) * 3
+    y1 = (y // 3) * 3
+    for xk in range(x1, x1 + 3):
+        for yk in range(y1, y1 + 3):
+            if (xk != x or yk != y) and feld[xk][yk] == feld[x][y]:
+                return False
+
+    return True
+
+def nextone(feld, x, y):
+    if y == 9:
+        y = 0
+        x += 1
+    if x == 9:
+        return True
+
+    if feld[x][y] > 0:
+        if not isfine(feld, x, y):
+            return False
+        return nextone(feld, x, y + 1)
+    else:
+        for feld[x][y] in range(1, 10):
+            if not isfine(feld, x, y):
+                continue
+            if nextone(feld, x, y + 1):
+                return True
+        feld[x][y] = 0
+        return False
+
+def main():
+    tstart = time.time()
+    
+    if nextone(start, 0, 0):
+        for row in start:
+            print(row)
+    else:
+        print("Nope!")
+
+    time1 = time.time()
+    print(f"{tstart} - {time1} * {time.CLOCKS_PER_SEC}")
+
+if __name__ == "__main__":
+    main()
+