#include <vector>
using namespace std;
-static const bool do_test2 = false; // set to true in order to run this beast
+constexpr bool do_test2 = false; // set to true in order to run this beast
static const symbol a1("a1"), a2("a2"), a3("a3"), a4("a4"), a5("a5"), a6("a6");
static const symbol b1("b1"), b2("b2"), b3("b3"), b4("b4"), b5("b5"), b6("b6");