#include<fstream.h>
ifstream f("text.in");
ofstream g("text.out");
int nr,cuv,l,i;
char s[100001];
int main()
{ f.getline(s,101);
  l=strlen(s);
  for(i=0;i<l;i++) if(((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z'))&&((s[i-1]<='a'||s[i-1]>='z')&&(s[i-1]<='A'||s[i-1]>='Z'))) { cuv++;
                                                                                                                            nr++;
                                                                                                                           }
	               else if(((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z'))&&((s[i-1]>='a'&&s[i-1]<='z')||(s[i-1]>='A'&&s[i-1]<='Z'))) nr++;
  cuv++;
  cuv/=2;
  g<<nr/cuv<<"\n";
  f.close();
  g.close();
  return 0;
}