O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O
O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O O+Y=O