#include <stdio.h>   
#include <string.h>   
  
int main()   
{   
 FILE *f,*g;   
 long n=-1,i=-1,l=0,c=0;   
 char *sir = new char[1000000];   
 f=fopen("text.in","r");   
 g=fopen("text.out","w");   
 while (!feof(f)) {++n;sir[n]=getc(f);};   
 sir[n+1]=' ';   
 fclose(f);   
 do   
 {   
  ++i;   
  if ((((int)sir[i]<123)&&((int)sir[i]>96))||(((int)sir[i]<91)&&((int)sir[i]>64))) ++l;   
  else if ((((int)sir[i+1]<123)&&((int)sir[i+1]>96))||(((int)sir[i+1]<91)&&((int)sir[i+1]>64))) ++c;   
  
 }   
 while (i<n);   
 fprintf(g,"%ld",l/c);   
 return 0;   
}