/* Average: calculates the mean of some numbers */

#include <stdio.h>
#include <math.h>

#define BUFSIZE 256

main () {
  char buffer[BUFSIZE];
  int i = 0;
  double size = 0;
  double sum = 0.0;
  double sqrsum = 0.0; 
  double var = 0.0;
  double sdev = 0.0;

  while (fgets(buffer, BUFSIZE,stdin))
    if (sscanf(buffer,"%lg", &size) > 0)
      {
    i++; 
    sum = sum + size;
    sqrsum = sqrsum + ( size * size);
  };
  
  var = ((i * sqrsum) - ( sum * sum)) / ( i * ( i - 1.0));
  sdev = (double) sqrt( (double) var );
  
  printf("Number of values: %d\n", i);
  printf("Sum: %lg\n", sum);
  printf("Mean: %lg\n", sum/i);
  printf("Variance: %lg\n", var);
  printf("StdDev: %lg\n", sdev);
}