y x2 // inspection
r (D U') R' U2 x' D2' // cross
U U R' U2 R U R' U' R // 1st pair
U' y' R U R' U2 L' U' L // 2nd pair
U' R U' R' U2 R U' R' // 3rd pair
U' U' R' U2 R U R' U' R // 4th pair
U r U R' U' r' R U R U' R' // OLL
U R U R' F' R U R' U' R' F R2 U' R' U'