#include <stdio.h>
#include <fstream.h>
#include <iomanip.h>

int main(void)
{
  char mj[20];
  cout << "\nAnna tiedoston nimi: ";
  cin >> mj;
  cout << "\nAvataan '" << mj << "'";

  ifstream fi(mj);
  if (!fi) {
    cout << "\nTiedostoa ei loytynyt!";
    return 1;
  }

  int i,lkm=0;
  double summa=0;
  while ( fi ) {
    fi >> i;
    summa+=i;
    lkm++;
  }

  if ( lkm != 0 ) {
    cout << "\nKeskiarvo ";
    cout.precision(3); cout.setf(ios::showpoint);
    cout << summa/lkm;
  }
  return 0;

}