#include <iostream>
#include <bits/stdc++.h>
using namespace std;
ifstream f ("text.in");
ofstream g ("text.out");
char a[255],*mi;
int suma,cuvant,i;
int main()
{
    f.getline(a,256);
    mi=strtok(a," -_,.!?()");
    while(mi!= NULL)
    {for(i=0;i<=strlen(mi);i++)
            if(((mi[i]>=90&&mi[i]<=65)&&(mi[i]>=122&&mi[i]<=97)))
        {
                cuvant++;
                suma--;
        }

        suma+=strlen(mi);
        cuvant++;
        mi=strtok(NULL," -_,.!?()");

    }
g<<suma/cuvant;

    /*while(cin>>a)
{cuvant++;
suma+=strlen(a);
//cout<<a<<" "<<cuvant<<endl;
    for(i=0;i<=strlen(a);i++)
    {if(a[i]!=' ')
    {
        if(!((a[i]<=90&&a[i]>=65)||(a[i]<=122&&a[i]>=97)))
        {if(a[i]!=' ')
            cout<<a[i]<<"miau";
            if(!(i==0||i==strlen(a)-1)&&a[i]!=' ')
            {
                cuvant++;
                suma--;
               // cout<<a[i]<<" "<<cuvant<<endl;
            }

        }
    }

    }

}
    //;
//
    cout << suma/cuvant<< endl;*/
    return 0;
}