#include <stdio.h>
#include <string.h>

int main()
{
 FILE *f,*g;
 long n=0,i=-1,l=0,c=1;
 char sir[1000000];
 f=fopen("text.in","r");
 g=fopen("text.out","w");
 while (!feof(f))
 {
  ++n;
  sir[n]=getc(f);
 }
 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;
}