#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll inf=1444999999994;
ll mod=1000000007;
int main(){
    string s;
    cin >> s;
    ll x=s.size();
    cout << x/2+x%2 << endl;
}