#include <fstream>
#include <cctype>

using namespace std;

ifstream fin( "text.in" );
ofstream fout( "text.out" );

int main() {
  int ncuv, lcuv, l;
  char ch;
  
  lcuv = ncuv = l = 0;
  ch = fin.get();
  while ( !fin.eof() ) {
	if ( isalpha( ch ) ) {
	  ++l;
	} else {
	  if ( l > 0 ) {
	    ++ncuv;
	  }
	  lcuv += l;
	  l = 0;
	}
    ch = fin.get();
  }
  fout << lcuv / ncuv;
  fin.close();
  fout.close();
  return 0;
}