z2 y // inspection
R D y' R' y D2 z' U' z D' // cross
U' R U' R' // 1st pair
U' R' U R U z U' R' U // 2nd pair
z' R' U R U' y U' R' U' R // 3rd pair
U' U' R U R' // 4th pair
U' r U R' U R U' U' r' r' U' R U' R' U' U' r // OLL
U R U R' y z U' U' r' U R' U' R U' r U' U' R'