#include <string.h>
#include <stdio.h>
#include <algorithm>
using namespace std;


FILE *in=fopen("text.in","r"),*out=fopen("text.out","w");
int cr=0,cuv=0,inwrd=0;

void _read()
{
  char ch;

  while(!feof(in))
  {
   fscanf(in,"%c",&ch);

   if( strchr("!.? ,;:", ch )== NULL && !inwrd )
    {
    cuv++;
    inwrd=1;
    }
  if( (ch>='a' && ch<='z') || (ch>='A' && ch<='Z') && inwrd)
    cr++;
  else
  if( strchr("!.? ,;:", ch )!= NULL )
    inwrd=0;


   }

}


int main()
{
 _read();


 fprintf(out,"%d",cr/cuv);

return 0;
}