#include <iostream>                // Ex34
#include <cmath>
using namespace std;
struct complex {
    double re, im;
    double abs() { return sqrt( re * re + im * im ); }
    complex() { re = 0.; im = 0.; } // overloaded constructors
    complex( double r ) { re = r; im = 0.; }
    complex( double r, double i ) { re = r; im = i; }
};