#include<fstream.h>
#include<string.h>

int main()
{
 ifstream fin("text.in");
 ofstream fout("text.out");
 char c;
 int lit=0,cuv=0,flag=0;
  while(fin.get(c))
  {
   if(strchr("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",c)!=NULL)
    {
    lit++;
    flag=1;
    }
     else
      if(strchr("~!@#$%^&*()_+{}:<>?`1234567890-=[];,./ ",c)!=NULL && flag)
       {
       cuv++;
       flag=0;
       }
   }
  if(!cuv)
   fout<<"";
   else
  fout<<lit/cuv;
 fin.close();
 fout.close();
return 0;
}