#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.size();
  int cnt = 1;
  for (int i = 1; i < n; i++) {
    if (s[i] == s[i - 1]) {
      i++;
    }
    cnt++;
  }
  cout << cnt << endl;
}
