#include <fstream>
#include <string>

using namespace std;

ifstream fin( "text.in" );
ofstream fout( "text.out" );

string s;

bool is_letter( char c )
{
   return ( 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' );
}

int main()
{
    int lg_tot, nr_c;

    lg_tot = nr_c = 0;

    while( getline( fin, s ) )
    {
      for( int i = 0; i < s.size(); ++i )
      {
        if( is_letter( s[i] ) )
        {
           ++nr_c;

           while( i < s.size() && is_letter( s[i] ) )
           {
             ++i;
             ++lg_tot;
           }
        }
      }
    }

    fout << lg_tot / nr_c << '\n';

    fin.close();
    fout.close();

    return 0;
}