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

int main() {
  string s;
  cin >> s;
  int a = 1;
  bool b = 0;
  for(int i = 1; i < s.size(); i++){
    if(b){
      b = 0;
      continue;
    }
    else if(s.at(i-1) != s.at(i))
      a++;
    else{
      a++;
      b = 1;
    }
  cout << a << endl;    
}
