diff --git a/src/lib.rs b/src/lib.rs
index a5b7e8f5..506a75b2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1494,6 +1494,7 @@ pub mod problem_2023_number_of_pairs_of_strings_with_concatenation_equal_to_targ
 pub mod problem_2024_maximize_the_confusion_of_an_exam;
 pub mod problem_2027_minimum_moves_to_convert_string;
 pub mod problem_2028_find_missing_observations;
+pub mod problem_2029_stone_game_ix;
 pub mod problem_2032_two_out_of_three;
 pub mod problem_2033_minimum_operations_to_make_a_uni_value_grid;
 pub mod problem_2034_stock_price_fluctuation;
diff --git a/src/problem_2029_stone_game_ix/mathematical.rs b/src/problem_2029_stone_game_ix/mathematical.rs
new file mode 100644
index 00000000..7c9f2ab8
--- /dev/null
+++ b/src/problem_2029_stone_game_ix/mathematical.rs
@@ -0,0 +1,38 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn stone_game_ix(stones: Vec<i32>) -> bool {
+        let mut counts = [0_u32; 3];
+
+        for stone in stones {
+            counts[usize::from(stone as u16 % 3)] += 1;
+        }
+
+        let [zero, one, two] = counts;
+        let (x, y) = if two < one { (two, one) } else { (one, two) };
+
+        if zero % 2 == 0 {
+            x != 0
+        } else {
+            y - x > 2
+        }
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn stone_game_ix(stones: Vec<i32>) -> bool {
+        Self::stone_game_ix(stones)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}
diff --git a/src/problem_2029_stone_game_ix/mod.rs b/src/problem_2029_stone_game_ix/mod.rs
new file mode 100644
index 00000000..3a25f65c
--- /dev/null
+++ b/src/problem_2029_stone_game_ix/mod.rs
@@ -0,0 +1,46 @@
+pub mod mathematical;
+
+pub trait Solution {
+    fn stone_game_ix(stones: Vec<i32>) -> bool;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (&[2, 1] as &[_], true),
+            (&[2], false),
+            (&[5, 1, 2, 4, 3], false),
+            (&[2, 2, 3], false),
+            (&[2, 2, 2, 3], true),
+            (
+                &[
+                    325, 348, 389, 196, 236, 79, 219, 29, 119, 354, 497, 203, 55, 333, 403, 180, 205, 80, 208, 310,
+                    416, 335, 392, 409, 485, 329, 379, 277, 403, 370, 194, 428, 491, 488, 152, 316, 268, 364, 69, 61,
+                    266, 335, 236, 240, 148, 352, 141, 276, 400, 397, 279, 408, 81, 320, 294, 395, 418, 277, 369, 364,
+                    83, 460, 364, 282, 223, 36, 449, 31, 303, 485, 455, 33, 437, 413, 462, 225, 183, 500, 316, 141,
+                    164, 60, 406, 254, 132, 407, 105, 343, 70, 363, 19, 500, 211, 199, 155, 477, 424, 101, 347, 402,
+                    469, 323, 192, 210, 224, 352, 348, 500, 282, 82, 262, 437, 438, 173, 236, 375, 38, 458, 436, 261,
+                    461, 271, 155, 488, 446, 418, 403, 482, 474, 46, 344, 480, 390, 357, 303, 57, 298, 31, 402, 460, 2,
+                    212, 285, 243, 110, 359, 81, 147, 308, 190, 341, 417, 99, 277, 42, 109, 51, 49, 487, 443, 143, 150,
+                    428, 129, 287, 348, 500, 203, 183, 74, 112, 228, 166, 21, 10, 355, 174, 91, 493, 124, 457, 254,
+                    478, 407, 277, 122, 403, 251, 144, 404, 430, 396, 336, 433, 100, 497, 127, 122, 300, 145, 234, 423,
+                    9, 467, 442, 290, 275, 329, 105, 115, 415, 41, 125, 471, 421, 247, 182, 158, 311, 39, 284, 291,
+                    243, 455, 124, 7, 462, 232, 62, 78, 437, 220, 266, 358, 473, 479, 417, 477, 447, 34, 295, 244, 173,
+                    77, 403, 483, 460, 396, 102, 205, 123, 259, 212, 461, 203, 33, 493, 301, 136, 5, 64, 104, 157, 337,
+                    318, 102, 44, 39, 246, 97, 334, 85, 407, 442, 168, 203, 466, 211, 463, 271, 450, 166, 374, 368,
+                    186, 137, 436, 246, 41, 90, 272, 220, 4, 69, 430, 319, 242, 13, 402, 426, 276, 13, 450, 223, 340,
+                    83, 394, 10, 69, 422, 230, 473, 414, 121, 297, 161, 458, 396, 413, 164, 475, 83, 111, 71, 397, 11,
+                    148, 433, 302, 99, 26, 232, 177, 45, 161, 223, 37, 398, 29, 200, 255, 257, 44, 402, 329, 290,
+                ],
+                true,
+            ),
+        ];
+
+        for (stones, expected) in test_cases {
+            assert_eq!(S::stone_game_ix(stones.to_vec()), expected);
+        }
+    }
+}