#include <stdio.h>
#include <string>

class Complex {
private:
    int a, b;

public:
    Complex(int real) {
        a = real;
        b = 0;
    }

    Complex(int real, int imag) {
        a = real;
        b = imag;
    }

    Complex(const Complex &c) {
        *this = c;
    }

    Complex &operator=(const Complex &c) {
        a = c.a;
        b = c.b;
        return *this;
    }

    Complex &operator+=(const Complex &c) {
        a += c.a;
        b += c.b;
        return *this;
    }

    Complex &operator-=(const Complex &c) {
        a -= c.a;
        b -= c.b;
        return *this;
    }

    Complex &operator*=(const Complex &c) {
        Complex tmp = *this;
        a = tmp.a * c.a - tmp.b * c.b;
        b = tmp.a * c.b + tmp.b * c.a;
        return *this;
    }

    std::string str() const {
        char buf[32];
        if (b == 0) {
            snprintf(buf, sizeof(buf), "%d", a);
        } else if (a == 0) {
            if (b == -1) return "-i";
            if (b ==  1) return  "i";
            snprintf(buf, sizeof(buf), "%di", b);
        } else if (b == -1) {
            snprintf(buf, sizeof(buf), "%d-i", a);
        } else if (b < 0) {
            snprintf(buf, sizeof(buf), "%d%di", a, b);
        } else if (b == 1) {
            snprintf(buf, sizeof(buf), "%d+i", a);
        } else {
            snprintf(buf, sizeof(buf), "%d+%di", a, b);
        }
        return buf;
    }
};

Complex operator+(const Complex &c1, const Complex &c2) {
    Complex ret = c1;
    ret += c2;
    return ret;
}

Complex operator-(const Complex &c1, const Complex &c2) {
    Complex ret = c1;
    ret -= c2;
    return ret;
}

Complex operator*(const Complex &c1, const Complex &c2) {
    Complex ret = c1;
    ret *= c2;
    return ret;
}

int main() {
    Complex i(0, 1);
    Complex a = 1 + 2*i;
    Complex b = 3 + 4*i;
    Complex c = a + b;
    Complex d = a * b;
    Complex e = a - 1;
    Complex f = a - 2*i;
    printf("a = %s\n", a.str().c_str());
    printf("b = %s\n", b.str().c_str());
    printf("c = %s\n", c.str().c_str());
    printf("d = %s\n", d.str().c_str());
    printf("e = %s\n", e.str().c_str());
    printf("f = %s\n", f.str().c_str());
}