U' R2 F' U B L' U L F D2 F2 L D2 B2 R' B2 R2 U2 B2 R
y2 // inspection
r U' y x' R' U // cross
z' D R' U R U' D' // 1st pair
z U R' U' // 2nd pair
z' R U' R' U R U' R' U R U' R' // 3rd pair
y' U' R U r' U' R U R R r // 4th pair+ZBLS
U' R U R' U R U R' U2' L R U' R' U' z U' R' U R' U' R // ZBLL