y x2 // inspection
r R' U x' D x U2' z U2' x' // cross
U R' U' R y z U' R' U z' // 1st pair
U' R U' R' U y R' U R // 2nd pair
D R U' R' D' // 3rd pair
U2' R U R' y' // EO
U2' R' U2 R U' R' U' R U2' R' U R // 4th pair
z u' R' U R z' R U' z U' R x' // COLL
R2 U' R' U' R U R U R U' R U'