#include <stdio.h>   
#include <string.h>
FILE *q,*w;
char s[20000],sep[]="_ 1234567890,.?/!;\'-@#$%^&*(){}[]|:<>+~`",*a;
int n,nr,nrc,l,i,se,j;
float r;
int main()
{q=fopen("text.in","r");
w=fopen("text.out","w");
while (!feof(q))
{fgets(s,20000,q);
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(w,"%d",int(r));
return 0;}