#include<fstream> 
#include<string.h> 
using namespace std; 
ifstream f ("text.in"); 
ofstream g ("text.out"); 
int nr,s,n,n1,i; 
char a[10000],*p,sep[]="!. ,:?-",sir[]="0123456789"; 
int main () 
{f.get(a,10000); 
p=strtok(a, sep);  
while ( p ) 
{n=strlen(p); 
n1=0;
for (i=0;i<n;i++)
	if (strchr(sir,p[i])==0)
		n1=n1++;
s=s+n1; 
nr++; 
p=strtok(NULL, sep);
} 
g<<s/nr; 
}