A Boring Game CP101

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define pb push_back
#define p_b pop_back
#define si stack<int>
#define sll stack<ll>
#define sc stack<char>
#define vi vector<int>
#define vll vector<ll>
#define mii map<int, int>
#define msi map<string, int>
#define mci map<char, int>
#define qc queue<char>
#define qi queue<int>
#define qll queue<ll>
using namespace std;

bool comp(long a, long b){
    return a > b;
}

int main(){
    string s;
    cin >> s;
    int i = 0;
    vector<long> v;
    while(i < s.length()){
        if(s[i] == 'a'){
            int j = i+1;
            int count = 1;
            while(j < s.length() && s[j] == 'a'){
                j++;
                count++;
            }

            v.pb(count);
            i += count;
        } else{
            i++;
        }
    }

    sort(v.begin(), v.end(), comp);
    long p = 0;
    for(int j = 0; j < v.size(); j++){
        p += (j%2 == 0) ? v[j] : 0;
    }

    cout << p << "\n";
    return 0;
}