#include <fstream>
#include <cstring>
using namespace std;
int i,cuvinte,lg,ap,x;
char v[1000001];
ifstream fin ("text.in");
ofstream fout ("text.out");

int main (){

    fin.get (v,1000001);

    x = strlen (v);
    for (i=0;i<=x;i++){
        if ( (v[i] >= 'a' && v[i] <= 'z') || (v[i]>='A' && v[i] <= 'Z')){
            ap++;
        }
        else{
            if ((v[i-1] >= 'a' && v[i-1] <= 'z') || (v[i-1]>='A' && v[i-1] <= 'Z')){
                cuvinte ++;
                lg += ap;
               // fout<<ap<<"\n";
            }

            ap = 0;
        }

    }
    fout<<lg/cuvinte;



/*    p = strtok (v," ");
    while (p != NULL){
        cuvinte++;
        lg += strlen (p);
        for (i=0;i<strlen(p);i++)
            fout<<p[i]<<" ";
        fout<<"\n";
        p = strtok (NULL, " ");
    }
*/




    return 0;
}