#include <iostream>
#include <fstream>
using namespace std;
int main ()
{
    unsigned long i,numar=0,numar2=0;
    ifstream f("text.in");
    char c;
    bool ultim=false;
    while(f.get(c))
        if((c>='a'&&c<='z')||(c>='A'&&c<='Z')){
            numar++;
            ultim=true;
        }
        else{
             if(ultim)
             {
                 ultim=false;
                 numar2++;
             }
            }
    if(ultim)
        numar2++;
    ofstream g("text.out");
    g<<numar/numar2;
    g.close();
    f.close();
    return 0;
}