X = RNDF()*4-2
Y = RNDF()*4-2@N
N = N+16
I = X+S*S-T*T
T = Y+S*T*2
S = I
IF N < #L&&S*S+T*T < 4 GOTO @N
GPSET X*50+99, Y*50+99, RGB(99 XOR N,N,N)
EXEC.