//GIVE ME AC!!!!!!!!!!!!!!!!!
#include<bits/stdc++.h>
#define ll long long
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
int main(){
    string s;
   cin>>s;
   int n=s.size();
    cout<<(n+1)/2<<endl;
}