#include<iostream>
#include<string>
#include<fstream>
using namespace std;

ifstream in("text.in");
ofstream out("text.out");
char a;


int main()
{

long long  sl=0,sc=0;


while(!in.eof())
{
    a=in.get();
    if( (a>='a' && a<='z') || (a>='A' && a<='Z') )
     {
         while( (a>='a' && a<='z') || (a>='A' && a<='Z') )
          {
              ++sl;
              a=in.get();

          }
        ++sc;
     }




}

out<<sl/sc;
 return 0;
 }