B"Rumors say that one of Kamal-ol-molk's paintings has been altered. A rectangular brush has been moved right and down on the painting. Consider the painting as a n xe2 x80 x89 xc3 x97 xe2 x80 x89m rectangular grid. At the beginning an x xe2 x80 x89 xc3 x97 xe2 x80 x89y rectangular brush is placed somewhere in the frame, with edges parallel to the frame, (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89x xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n, xe2 x80 x891 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89y xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m). Then the brush is moved several times. Each time the brush is moved one unit right or down. The brush has been strictly inside the frame during the painting. The brush alters every cell it has covered at some moment. You have found one of the old Kamal-ol-molk's paintings. You want to know if it's possible that it has been altered in described manner. If yes, you also want to know minimum possible area of the brush. The first line of input contains two integers n and m, (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n, xe2 x80 x89m xe2 x80 x89 xe2 x89 xa4 xe2 x80 x891000), denoting the height and width of the painting. The next n lines contain the painting. Each line has m characters. Character 'X' denotes an altered cell, otherwise it's showed by '.'. There will be at least one altered cell in the painting. Print the minimum area of the brush in a line, if the painting is possibly altered, otherwise print xe2 x80 x89- xe2 x80 x891."...