diff --git a/src/main.rs b/src/main.rs
index 6e6cb60..137ad18 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,32 +1,30 @@
 mod arr;
 struct Solution {}
 impl Solution {
-    pub fn smallest_palindrome(s: String) -> String {
-        let mut arr = vec![0; 26];
-        let mut s = s.chars().collect::<Vec<char>>();
-        for i in 0..s.len() / 2 {
-            arr[(s[i] as u8 - b'a') as usize] += 1;
-        }
-        let mut idx = 0;
-        for i in 0..26 {
-            while arr[i] > 0 {
-                s[idx] = (b'a' + i as u8) as char;
-                arr[i] -= 1;
-                idx += 1;
+    pub fn max_active_sections_after_trade(s: String) -> i32 {
+        let (mut last_zero_count, mut zero_count) = (0,0);
+        let mut ans = 0;
+        let mut max_p = 0;
+        for c in s.chars() {
+            if c == '0' {
+                zero_count += 1;
+            }else {
+                ans += 1;
+                if zero_count > 0{
+                    if last_zero_count > 0 {
+                        max_p = max_p.max(last_zero_count + zero_count);
+                    }
+                    last_zero_count = zero_count;
+                    zero_count = 0
+                }
             }
         }
-        let mut rev_idx = idx;
-        if s.len() % 2 != 0{
-            idx += 1;
+        if zero_count > 0 && last_zero_count > 0 {
+            max_p = max_p.max(zero_count + last_zero_count);
         }
-        while rev_idx > 0{
-            rev_idx -= 1;
-            s[idx] = s[rev_idx];
-            idx += 1;
-        }
-        s.into_iter().collect::<String>()
+        ans + max_p
     }
 }
 fn main() {
-    println!("{:?}", Solution::smallest_palindrome("bahaahab".to_string()));
+    println!("{:?}", Solution::max_active_sections_after_trade("0100".to_string()));
 }