Given a string s consisting only of letters 'a' and 'b'. In a single step you can remove one palindromic **subsequence** from s.

Return the minimum number of steps to make the given string empty.

A string is a subsequence of a given string, if it is generated by deleting some characters of a given string without changing its order.

A string is called palindrome if is one that reads the same backward as well as forward.

**Example 1:**

**Input:** s = "ababa"
**Output:** 1
**Explanation:** String is already palindrome

**Example 2:**

**Input:** s = "abb"
**Output:** 2
**Explanation:** "**a**bb" -> "**bb**" -> "".
Remove palindromic subsequence "a" then "bb".

**Example 3:**

**Input:** s = "baabb"
**Output:** 2
**Explanation:** "**baa**b**b**" -> "b" -> "".
Remove palindromic subsequence "baab" then "b".

**Constraints:**

1 <= s.length <= 1000

s[i] is either 'a' or 'b'.

**Solution:**

```
class Solution {
public int removePalindromeSub(String s) {
if(s.length()==0) return 0;
StringBuilder sb=new StringBuilder(s);
if(sb.reverse().toString().equals(s)) return 1;
return 2;
}
}
```

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