#include <complex.h>
#include <stdio.h>

int main(void) {
    complex double x, y, z;
    x = 3.14159 - 2 * _Complex_I;
    y = 2.71828182 - _Complex_I;
    z = x - 2*y; printf("x - 2y = %f%+fi\n", creal(z), cimag(z));
}