long f1(long,long,long);
long f2(long,long,long);
long f3(long,long,long);
long f4(long,long,long);
long f5(long,long,long);
long f6(long,long,long);
long f7(long,long,long);
long f8(long,long,long);

RET(
f1(0,0,0) == 1 && f1(0,1,1) == 0 &&
f2(0,0,0) == 0 && f2(0,1,1) == 1 &&

f3(0,4,4) == 1 && f3(0,4,3) == 0 &&
f4(0,4,4) == 0 && f4(0,4,3) == 1 &&

f5(0,5,4) == 1 && f5(0,4,5) == 0 &&
f6(0,5,4) == 0 && f6(0,4,5) == 1 &&

f7(0,5,4) == 1 && f7(0,5,5) == 0 &&
f8(0,5,4) == 0 && f8(0,5,5) == 1 
);