The marked price of two items, 'S' and 'R,' is identical. Item 'S' is sold with a single discount of 18%, while item 'R' is sold with two successive discounts of 10% and 20%. The difference in the selling prices of the two items is ₹400. Additionally, the combined cost price of both items is ₹4000. Determine whether there is an overall profit or loss from selling both items and by how much.