#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
long long nr=0,nr1=0,s,ok=0;
char c;
int main()
{
   while (!f.eof())
   {
       f.get(c);
       if(c>='a'&&c<='z' || c>='A'&&c<='Z' )
       {
           nr1++;

       }
       else
       { s=s+nr1;
           if(nr1!=0)nr++;
           nr1=0;
       }

   }
   g<<s/nr;
    return 0;
}