#include <fstream>
#include <string.h>

using namespace std;
ifstream f("text.in");
ofstream g("text.out");
char a[500];
unsigned int n=0,nr=0,i;
int main()
{
    while(!f.eof())
        {f.getline(a,500);

        for(i=0;i<strlen(a);i++)
            {
             if((a[i]>='a'&&a[i]<='z')||(a[i]>='A'&&a[i]<='Z'))
                 {while((a[i]>='a'&&a[i]<='z')||(a[i]>='A'&&a[i]<='Z'))
                       {i++;
                        nr++;}
                  n++;
                  i--;}
            }
      }
    g<<nr/n;
    f.close();
    g.close();
}