#include <bits/stdc++.h>
using namespace std;

int main() {
  string S;
  cin >> S;
  set<pair<int, int>> SE;
  SE.insert({0, 0});
  for (int i = 0, f = 0, a = 0, b = 1, c = 2, x = 0, y = 0; i < S.size(); i++, f ^= 1) {
    int s = S[i] - 'a';
    if (s == a) (f) ? SE.insert({x, ++y}) : SE.insert({x, --y});
    else if (s == b) SE.insert({--x, y}), swap(a, b), swap(a, c);
    else SE.insert({++x, y}), swap(a, c), swap(a, b);
  }
  cout << SE.size() << "\n";
}