($x1,$y1,$z1)=glob<>;
($x2,$y2,$z2)=glob<>;
($x3,$y3,$z3)=glob<>;
($x4,$y4,$z4)=glob<>;

$x12=$x2-$x1;
$y12=$y2-$y1;
$z12=$z2-$z1;
$x23=$x3-$x2;
$y23=$y3-$y2;
$z23=$z3-$z2;
$x31=$x1-$x3;
$y31=$y1-$y3;
$z31=$z1-$z3;
$nx=$y12*$z23-$y23*$z12;
$ny=$z12*$x23-$z23*$x12;
$nz=$x12*$y23-$x23*$y12;
$n12x=$ny*$z12-$nz*$y12;
$n12y=$nz*$x12-$nx*$z12;
$n12z=$nx*$y12-$ny*$x12;
$n23x=$ny*$z23-$nz*$y23;
$n23y=$nz*$x23-$nx*$z23;
$n23z=$nx*$y23-$ny*$x23;
$n31x=$ny*$z31-$nz*$y31;
$n31y=$nz*$x31-$nx*$z31;
$n31z=$nx*$y31-$ny*$x31;
$x41=$x1-$x4;
$y41=$y1-$y4;
$z41=$z1-$z4;
$x42=$x2-$x4;
$y42=$y2-$y4;
$z42=$z2-$z4;
$x43=$x3-$x4;
$y43=$y3-$y4;
$z43=$z3-$z4;
$s1=$x41*$n12x+$y41*$n12y+$z41*$n12z > 0;
$s2=$x42*$n23x+$y42*$n23y+$z42*$n23z > 0;
$s3=$x43*$n31x+$y43*$n31y+$z43*$n31z > 0;

print $s1==$s2&&$s1==$s3?YES:NO