#include <stdio.h>   
 #include <string.h>   
 FILE *in,*o;   
 char s[10000],sep[]="_ 1234567890,.?/!;\'-@#$%^&*(){}[]|:<>+~`",*a;   
 int n,nr,nrc,l,i,se,j;   
 float r;   
 main()   
 {   
 in=fopen("text.in","r");   
 o=fopen("text.out","w");   
 while (!feof(in))   
 {   
 fgets(s,10000,in);   
 n=strlen(s);   
 for (i=0;i<n;i++)   
  {   
  if (s[i]<='z' && s[i]>='a' || s[i]<='Z' && s[i]>='A')   
   nr++;   
  }   
 a=strtok(s,sep);   
 if (a!=NULL)   
  nrc++;   
 while (a!=NULL)   
  {nrc++;   
  a=strtok(NULL,sep);   
  }   
 nrc--;   
 }   
 r=nr/nrc;   
 fprintf(o,"%d",int(r));   
 fclose(in);   
 fclose(o);   
 return 0;   
 }