#include <fstream>

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

char X[1100000];
int NrCuvinte, NrLitere, i;
int main()
{
    while(fin.getline (X, 1100000))
    {
      for (i=0; X[i]!=0; i++)
      {
        if (('a'<=X[i] and X[i]<='z') or ('A'<=X[i] and X[i]<='Z'))
        {
          NrCuvinte++;
          while (('a'<=X[i] and X[i]<='z') or ('A'<=X[i] and X[i]<='Z'))
          {
            NrLitere++;
            ++i;
          }
          i--;
        }
      }
    }
    fout<<NrLitere/NrCuvinte<<"\n";
    return 0;
}