PD[
X[1,9,2,8],
X[7,3,8,2],
X[32,9,33,10],
X[15,11,16,10],
X[31,7,32,6],
X[16,5,17,6],
X[20,33,21,34],
X[19,15,20,14],
X[23,35,24,34],
X[24,13,25,14],
X[21,29,22,28],
X[27,23,28,22],
X[36,29,1,30],
X[3,31,4,30],
X[4,17,5,18],
X[11,19,12,18],
X[12,25,13,26],
X[35,27,36,26]
]
