z y2 // inspection
U2' R2' // red cross
y' U2' R U' R' U R U' R' // 1st pair
U2' R' U' R U R' U' R // 2nd pair
z x' R' U' R U R' U' R U // 3rd pair
z' y' U R' U' R U2' R' U R // 4th pair
U2 R' U' R' x U R U' x' U R // OLL
U y2' r r' R2 u' R U' R U R' u R2 y R U' R' // PLL