F R D R2 U2 L2 B2 D' F2 D B2 U2 F2 R2 F U R' U' B' R
x' z' // inspection
D2 R' U F D2 // cross
R U' R' U' U' R U R' // 1st pair
y' U' U' R U' R' U R U' R' U' U' R U' R' // 2nd pair
z U' R' U R z' y' R U' R' // 3rd pair
y' R U' R' U y' R' F' U' F R // 4th pair/ZBLS
U' U' x' U' R U' R' U R' F' F' R U' R U R' U // ZBLL