#include <cstdio>
using namespace std;

int
main () {
  FILE * io = fopen ("text.in", "r");

  int s=0, n=0, m = 0;
  char ch;

  ch = fgetc(io);
  do {
    while ( EOF != ch && 
            !('a' <= ch && 'z' >= ch) && 
            !('A' <= ch && 'Z' >= ch)    ) { ch = fgetc(io); } // while
    
    while ( ('a' <= ch && 'z' >= ch) ||
            ('A' <= ch && 'Z' >= ch)    ) { ch = fgetc(io); ++ m; }
    if (0 < m) {
      ++ n; s += m; m = 0;
    }
  } while (! feof (io));
  fclose(io);
  if (0 < n) m = s / n; else m = 0;
  io = fopen ("text.out", "w");
  fprintf (io, "%d\n", m);
  fclose (io);
  return 0;
}