#include <iostream>
#include <string>
#include <vector>
using namespace std;
 
int main() {
 int a, b, count = 1;
 vector <int> vec;
 string str;
 getline(cin, str);
 int n = str.length();
 for (int i = 1; i < n; i++) if (str[i - 1] != str[i]) {
        vec.push_back(count);
        count = 1;
    } else count++;
 vec.push_back(count);
 cin >> a >> b;
 int sum = 0;
 for (int e : vec) sum += e;
 int len = vec.size();
 cout << a * sum + ((b < 0) ? (len / 2 + 1) : len) * b;
 return 0;
}

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