#include <stdio.h>

int main() {

  double a = -0.0;
  double b = +0.0;

  printf("a = %+.2lf\n", a);
  printf("b = %+.2lf\n", b);
  printf("a + b = %+.2lf\n", a + b);
  printf("b + a = %+.2lf\n", b + a);

  return 0;
}

a = -0.00
b = +0.00
a + b = +0.00
b + a = +0.00