#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;
}