#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000


int main(){

	string s;
	cin>>s;
	
	int ans = s.size();
	
	cout<<(1+ans)/2<<endl;
	
    return 0;
}