#define A1    1
#define A2()  1
#define A3(x) 1

#define B1    { f(1); f(2); }
#define B2()  { f(1); f(2); }
#define B3(x) { f(1); f(2); }

#define C1    a = b
#define C2()  a = b
#define C3(x) a = b
