<p>You are given a string <code>s</code> and two integers <code>x</code> and <code>y</code>. You can perform two types of operations any number of times.</p>

<ul>
	<li>Remove substring <code>&quot;ab&quot;</code> and gain <code>x</code> points.

	<ul>
		<li>For example, when removing <code>&quot;ab&quot;</code> from <code>&quot;c<u>ab</u>xbae&quot;</code> it becomes <code>&quot;cxbae&quot;</code>.</li>
	</ul>
	</li>
	<li>Remove substring <code>&quot;ba&quot;</code> and gain <code>y</code> points.
	<ul>
		<li>For example, when removing <code>&quot;ba&quot;</code> from <code>&quot;cabx<u>ba</u>e&quot;</code> it becomes <code>&quot;cabxe&quot;</code>.</li>
	</ul>
	</li>
</ul>

<p>Return <em>the maximum points you can gain after applying the above operations on</em> <code>s</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;cdbcbbaaabab&quot;, x = 4, y = 5
<strong>Output:</strong> 19
<strong>Explanation:</strong>
- Remove the &quot;ba&quot; underlined in &quot;cdbcbbaaa<u>ba</u>b&quot;. Now, s = &quot;cdbcbbaaab&quot; and 5 points are added to the score.
- Remove the &quot;ab&quot; underlined in &quot;cdbcbbaa<u>ab</u>&quot;. Now, s = &quot;cdbcbbaa&quot; and 4 points are added to the score.
- Remove the &quot;ba&quot; underlined in &quot;cdbcb<u>ba</u>a&quot;. Now, s = &quot;cdbcba&quot; and 5 points are added to the score.
- Remove the &quot;ba&quot; underlined in &quot;cdbc<u>ba</u>&quot;. Now, s = &quot;cdbc&quot; and 5 points are added to the score.
Total score = 5 + 4 + 5 + 5 = 19.</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;aabbaaxybbaabb&quot;, x = 5, y = 4
<strong>Output:</strong> 20
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= x, y &lt;= 10<sup>4</sup></code></li>
	<li><code>s</code> consists of lowercase English letters.</li>
</ul>

class Solution {
public:
    int maximumGain(string s, int x, int y) {
       stack<char>st;
       int ans=0;
       for(int i=0;i<s.length();i++)
       {
           if(!st.empty() && st.top()=='a' && s[i]=='b')
           {
            ans+=x;
            st.pop();
           }
           else
           st.push(s[i]);
       }
       string str=""; 
       while(!st.empty())
       {
        str+=st.top();
        st.pop();
       }
       reverse(str.begin(),str.end());
       for(int i=0;i<str.length();i++)
       {
        if(!st.empty() && st.top()=='b'&& str[i]=='a')
          {
            ans+=y;
            st.pop();
          }
          else
          st.push(str[i]);
       }



        stack<char>ste;
       int ans2=0;
       for(int i=0;i<s.length();i++)
       {
           if(!ste.empty() && ste.top()=='b' && s[i]=='a')
           {
            ans2+=y;
            ste.pop();
           }
           else
           ste.push(s[i]);
       }
       string str1=""; 
       while(!ste.empty())
       {
        str1+=ste.top();
        ste.pop();
       }
       reverse(str1.begin(),str1.end());
       for(int i=0;i<str1.length();i++)
       {
        if(!ste.empty() && ste.top()=='a'&& str1[i]=='b')
          {
            ans2+=x;
            ste.pop();
          }
          else
          ste.push(str1[i]);
       }
        cout<<ans<<" "<<ans2<<endl;
       return max(ans,ans2);



    }
};
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