x y2
//
inspection
R U z' R' U y' R' z R' D
//
cross
U' U' R' U R
//
1st pair
U R U' R' z U R' U'
//
2nd pair
z' y' U' U U' R' U R U' R' U R
//
3rd pair
U' U' R U' R' U' U' R U' R'
//
4th pair
U R' U' U R U' U' R U R' z U' R' R' z' R U R' z R U R' U' R2 U
//
ZBLL