#include <fstream>
#include <iostream>
#include <cstring>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");

int main(){

    char T[2000001];
    long lit, cuv;
    long pointer;
    long x;
    long lung;

    f.getline(T,2000000,'\0');
    f.close();

    pointer=0;
    lit=0;
    cuv=0;
    lung=strlen(T);

    while (pointer<=lung){
        x=0;
        while (((T[pointer]>='a')&&(T[pointer]<='z'))||((T[pointer]>='A')&&(T[pointer]<='Z'))){
            x++;
            pointer++;
        }
        if (x>0){
            lit+=x;
            cuv++;
        }
        pointer++;
    }

    g<<lit/cuv<<"\n";
    g.close();

    return 0;
}