#include <fstream>
#include <cmath>
#include <vector>
#include <algorithm>
#include <map>
#include <string>
#include <bitset>
#define pb(a) push_back(a)
using namespace std;

ifstream cin("text.in");
ofstream cout("text.out");

string a;
long long lungime;
vector <string> cuvinte;

bool is_digit1(char a){
    return a >= 'A' && a <= 'Z';
}

bool is_digit2(char a){
    return a >= 'a' && a <= 'z';
}

vector <string> exploade(string a){
    vector <string> ans;
    string cuv = "";
    for(int i = 0; i < a.size(); ++i){
        if(is_digit1(a[i]) || is_digit2(a[i])){
            cuv += a[i];
        }
        else{
            if(cuv.size() > 0){
                ans.pb(cuv);
                cuv = "";
            }
        }
    }
    if(cuv.size() > 0){
        ans.push_back(cuv);
    }
    return ans;
}

int main(){
    getline(cin, a);
    cuvinte = exploade(a);
    for(int i = 0; i < cuvinte.size(); ++i){
        lungime += cuvinte[i].size();
    }
    if(cuvinte.size() == 0 || lungime == 0){
        cout << 0;
    }
    else{
        cout << lungime / cuvinte.size();
    }
    return 0;
}