x1 = s3 x2 = s27 x3 = s45 x4 = s47 x5 = s48 x6 = s50 x7 = s51 x8 = s52 x9 = s57 x10 = s58 x11 = s60 x12 = s61 x13 = s62 x14 = s63 x15 = s64 x16 = s65 x17 = s66 x18 = s116 x19 = s117 x20 = s118