L2 B2 R' D2 R F2 D2 L B L2 D L' R B2 U' L' F' D U'
x' y2 // inspection
l' U L2 F2' R' F // cross
R U' R' U R' U' R // 1st pair
u' R U' R' U R U' R' D // 2nd pair
y' R U2' R2' U' R // 3rd pair
d R' U R U' R' U' R // 4th pair/ZBLS
R' U2' R U R' U' R' D' R U2 R' D R2 U' // ZBLL