#include <complex>
#include <cstdio>

int
main()
{
    std::complex<double> z(2,3);

    printf("z = (%lf, %lf)\n", z.real(), z.imag());

    z = std::complex<double>(4,-3);
    printf("z = (%lf, %lf)\n", z.real(), z.imag());
}