#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
int main(){
    char s;
    int counter1=0,counter2=0;
    while(fin>> noskipws >>s){
        if(isalpha(s)){
            counter1++;
            while(isalpha(s)){
                counter2++;
                fin>>noskipws>>s;
            }
        }
    }
    fout<<counter2/counter1;
    fin.close();
    fout.close();
    return 0;
}