#include<stdio.h>

int main()
{
  int lit=0, cuv=0, cur=0;
  FILE*f=fopen("text.in","r");
  char x;
  while(!feof(f)) {
    fscanf(f,"%c",&x);
    if( (x>='a' && x<='z') || (x>='A' && x<='Z')) cur++;
    else if(cur) { lit+=cur; cuv++; cur=0; }
  }
  lit+=cur;

  freopen("text.out","w",stdout);

  if( !cuv) printf("0\n");
  else printf("%d\n",lit/cuv);
  fclose(f);

  return 0;
}