#include<stdio.h>   
#include<string.h>   
  
  
  
FILE *f=fopen("text.in","r"), *g=fopen("text.out","w");   
  
char s1,s2; 
int d,i,lit,nrcuv;   
  
  
int litera(char x)   
{if(x>='A' && x<='z')return 1;   
else return 0;}   
  
  
  
  
  
  
int main(){   
  
while(!feof(f)){   
 fscanf(f,"%c %c",&s1,&s2);
 
if(litera(s1))lit++;
if(litera(s2))lit++;
if(litera(s1)==1 && litera(s2)==0)nrcuv++;  
s1=s2;
fscanf(f,"%c",&s2);
} 
  
   
  
fprintf(g,"%d",lit/nrcuv);   
  
return 0;}