Given a string S. In one operation, you can remove the substring "pr" from the string S and get amount X or you can remove the substring "rp" and get the amount Y.
Find the maximum amount you can get if you perform zero or more such operations optimally.
Note :
Substring of a string S is defined as a continuous sequence of characters in S.
After removing pr or rp, the order of remaining letters should remain the same.
Example 1:
Input:
X = 5, Y = 4
S = "abppprrr"
Output: 15
Explanation:
Here, S = "abppprrr"
X= 5, Y=4.
Remove "pr", new string S = "abpprr".
Remove "pr", new string S = "abpr".
Remove "pr", new string S = "ab".
In total, we removed "pr" 3 times,
so total score is 3X + 0Y = 3*5 =15.

Example 2:
Input:
X = 7, Y = 7
S = "prpptppr"
Output: 14
Explanation:
Here, S = "prpptppr"
X= 7, Y=7.
As both have the same amount we can first
remove either pr or rp. Here we start with pr
Remove "pr", new string S = "pptppr".
Remove "pr", new string S = "pptp".
In total, we removed "pr" 2 times,
so total score is 2X + 0Y = 2*7 =14.
Your Task:
You don't need to read input or print anything. Your task is to complete the function solve() which takes the X ,Y and string S as input parameters and returns the maximum amount you can get after performing the above operations.
Expected Time Complexity: O(|S|)
Expected Auxiliary Space: O(|S|)
Constraints:
1 ≤ |S| ≤ 10^{5}
1 ≤ X,Y ≤ 10^{5}
S contains lowercase English letters only.

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