#include <iostream>
#include <ginac/ginac.h>
using namespace GiNaC;

int main(int argc, char* argv[])
{
    int N = 4;

    ex e, f, s, a0, a1;
    a0 = symbol("a0");
    a1 = symbol("a1");
    e = a0 + a1;
    f = 0;
    for (int i = 2; i < N; i++) {
        s = sqrt(ex(3))*symbol("a"+std::to_string(i));
        e = e + s;
        f = f - s;
    }
    e = expand(e * e);
    e = e.subs(a0 == f);
    e = expand(e);
    std::cout << e << std::endl;

    return 0;
}