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

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