#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  string prev = "";
  int n = s.size();
  int ans = 1;
  for (int i = 0; i < n - 1; ++i) {
    if (s[i] == s[i + 1]) {
      ++i;
      ++ans;
    } else {
      ++ans;
    }
  }
  cout << ans << endl;
  return 0;
}
