/*
 *Author - Amarjeet Sinha
 */
  #include<bits/stdc++.h>
  #define ll long long 
  #define hell 1000000007 
  #define F first
  #define re 15000000
  #define S second
  #define pb push_back
  #define all(a)  (a).begin(),(a).end()
  #define rep(i,a,b) for(ll int i = a;i<b;i++)
  #define pi 3.1415926536
  #define Mod 998244353
 // #define npos NULL
  //char a[2000][2000];
  using namespace std;
  int sum (ll a)
  {
      int sum =0;
      while(a>0)
      {
          sum = sum + (a%10);
          a=a/10;
      }
      return sum;
  }
  int count_digit(ll n)
  {
     int  count =0;
      while(n>0)
      {
          n = n/10;
          count++;
          //count++;
      }
      return count;
  }
  int binarySearch(int x,int y ,ll z ,ll v[])
  {
      int low = x;
      int high = y;
      int mid = x+(y-x)/2;
      while(low<=high)
      {
          if(v[mid]==z)
              return mid;
          if(v[mid]<z)
              return binarySearch(mid+1,high,z,v);
          if(v[mid]>z)
              return binarySearch(low,mid-1,z,v);
      }
      return -1;
  }
  ll modularExponentiation(ll x,ll n,ll M)
  {
      if(n==0)
          return 1;
      else if(n%2 == 0)        //n is even
          return modularExponentiation((x*x)%M,n/2,M);
      else                             //n is odd
          return (x*modularExponentiation((x*x)%M,(n-1)/2,M))%M;
 
  } 
  ll binaryExponentiation(ll x,ll n)
  {
      if(n==0)
          return 1;
      else if(n%2 == 0)        //n is even
          return binaryExponentiation(x*x,n/2);
      else                             //n is odd
          return x*binaryExponentiation(x*x,(n-1)/2);
  }
 
 
 
 
  set<ll> s;
  //vector<ll> v;
  void genrate(ll n,int len,int max)
  {
      if(len>max)
          return ;
      s.insert(n);
      genrate(n*10+1,len+1,max);
      genrate(n*10+0,len+1,max);
  }
  bool visited[200005];
  vector<ll> v[200005];
  bool recur[200005];
  //memset(level,0,sizeof(level));    
  /*void topological_sort(int x)
  {
      visited[x] = 1;
    //  sort(all(v[x]));
      for(int i =0;i<v[x].size();i++)
      {
          if(visited[v[x][i]]!=1){
              //level[v[x][i]] = level[x]+1;
              topological_sort(v[x][i]);
          }
      }
      ans.pb(x);
  }*/
  //char a2001][2001];
  ///**************** Cycle using DSU *********************///
 
  int findPivot(ll a[],int low,int high)
  {
      int mid = (low+high)/2;
      if(high < low)
        return -1;
       if(low == high)
        return low;
      if(a[mid] >= a[mid+1] && mid < high)
        return mid;
       if(a[mid-1] >=a[mid] && mid > low)
        return mid-1;
       if(a[mid] >= a[low])
       if(a[mid] <= a[low])
        return findPivot(a,low,mid-1);
  }
bool check(string s ,int mid){
   string prev = "";
   int cnt = 0;
   string res = "";
   for(int i = 0;i<s.size();i++){
        res.pb(s[i]);
        if(res!=prev){
          cnt++;
          prev = res;
          res = "";
          continue;
        }
        else
          continue;
   }
   if(cnt >= mid)
      return 1;
    else
      return 0;
}
  int main()
  {   
      ios_base::sync_with_stdio(false);
      cin.tie(0);
      cout.tie(0);            
      //std::setprecision(20);    
      int tests=1;
        //freopen("input.txt", "r", stdin);
     //  cin>>tests;
       
     while(tests--) 
      {  
        string s;
        cin>>s;
        set<string> stk;
        int low = 0,high = s.size();
        while(high-low > 5){
          int mid = (low+high)/2;
          if(check(s,mid))
             low = mid;
          else
             high = mid-1;
        }
        for(int i = high;i>=low;i--){
          if(check(s,i))
              {
                cout<<i;
                exit(0);
              }
        }
      }
}

Measured memory_bytes: 5524