using namespace std;
#include<fstream>
char s[4],p[4];
int contor, nrcuv;   
int main()
{
  ifstream fin("text.in");
  ofstream fout("text.out");
  do
  {
    fin.get(s,2);
    if((s[0]>='A'&&s[0]<='Z')||(s[0]>='a'&&s[0]<='z')) contor++;
      else if(((s[0]==' ')||(s[0]==',')||(s[0]=='-')||(s[0]==';')||(s[0]=='"'))&&((p[0]>='A'&&p[0]<='Z')||(p[0]>='a'&&p[0]<='z'))) nrcuv++;
    p[0]=s[0];
  }
  while(s[0]!='\0');
  fout<<contor/++nrcuv<<"\n";
  fin.close();
  fout.close();
  return 0;
}