#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
char ch[N];
int main() {
  scanf("%s", ch + 1);
  int l = strlen(ch + 1);
  int Ans = 1, opt = 1;
  for (int i = 2; i <= l;)
    if (!opt)
      Ans++, i++, opt = 1;
    else if (ch[i] != ch[i - 1])
      Ans++, i++;
    else
      Ans++, i += 2, opt = 0;
  cout << Ans << endl;
}
