#include <stdio.h>

int n;
int a[1000];

int main(void) {
  scanf("%d", &n);
  double x = 0;
  double y = 0;
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    x += i;
    y += a[i];
  }
  x /= n;
  y /= n;
  double sxy = 0;
  double sxx = 0;
  for (int i = 0; i < n; i++) {
    sxy += (i - x) * (a[i] - y);
    sxx += (i - x) * (i - x);
  }
  double A = sxy / sxx;
  double B = y - A * x;
  double C = 0;
  for (int i = 0; i < n; i++) {
    double d = a[i] - (A * i + B);
    C += d * d;
  }
  printf("%.16f %.16f\n%.16f\n", B, A, C);
  return 0;
}