RES
1b:x-dxyl-PEN-x:x
2b:b-dxyl-PEN-1:5
3b:b-dxyl-PEN-1:5
4b:b-dxyl-PEN-1:5
LIN
1:1o(3+1)2d
2:1o(4+1)3d
3:3o(4+1)4d