diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index 60dd272..5eb218c 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -71,4 +71,5 @@ mod p2834_find_the_minimum_possible_sum_of_a_beautiful_array;
 mod p2386_find_the_k_sum_of_an_array;
 mod p299_bulls_and_cows;
 mod p2129_capitalize_the_title;
-mod p1261_find_elements_in_a_contaminated_binary_tree;
\ No newline at end of file
+mod p1261_find_elements_in_a_contaminated_binary_tree;
+mod p2864_maximum_odd_binary_number;
\ No newline at end of file
diff --git a/src/problem/p2864_maximum_odd_binary_number.rs b/src/problem/p2864_maximum_odd_binary_number.rs
new file mode 100644
index 0000000..249e953
--- /dev/null
+++ b/src/problem/p2864_maximum_odd_binary_number.rs
@@ -0,0 +1,52 @@
+/**
+ * [2864] Maximum Odd Binary Number
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn maximum_odd_binary_number(s: String) -> String {
+        let nums: Vec<u32> = s.chars()
+            .map(|c| c.to_digit(10).unwrap())
+            .collect();
+
+        let mut one_count = 0;
+        let mut zero_count = 0;
+
+        for num in &nums {
+            if *num == 1 {
+                one_count += 1;
+            } else if *num == 0 {
+                zero_count += 1;
+            }
+        }
+
+        let mut result: Vec<char> = Vec::with_capacity(nums.len());
+
+        for _ in  1..one_count {
+            result.push('1');
+        }
+
+        for _ in 0..zero_count {
+            result.push('0');
+        }
+
+        result.push('1');
+        result.iter().collect()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_2864() {
+        assert_eq!("001", Solution::maximum_odd_binary_number("010".to_owned()));
+        assert_eq!("1001", Solution::maximum_odd_binary_number("0101".to_owned()));
+    }
+}