# include <stdio.h>   
# include <string.h>   
long int k,l,ok,i,q;   
char a[1000000],x;   
int main ()   
{   
freopen ("text.in","r",stdin);   
freopen ("text.out","w",stdout);   
while (scanf ("%s",&a)&& x!='\n')   
{   
if (scanf ("%c",&x))   
for (i=0;i<strlen(a);i++)   
{q=0;   
if ((a[i]>='a' && a[i]<='z') || (a[i]>='A' && a[i]<='Z'))   
{   
k++;   
ok=1;   
q=1;   
}   
else  
if (ok==1)   
{   
l++;   
ok=0;   
}   
}   
if (q==1)   
l++;   
}   
printf ("%li",k/l);   
return 0;   
}