Misha scored a carnation in a plate, and Masha pull a thread around them and get a convex polygon, which is a smaller stud. Since Misha once again watch soccer and he has no time, help them calculate the area of ​​a polygon of minimal area, thereby checking the quality of work meet the following Masha. \InputFile The first line of each test case contains a number of goals Mischa nails \textbf{N} (\textbf{4} ≤ \textbf{N} ≤ \textbf{10^5}). In the next \textbf{N} lines for each test case there are \textbf{N} pairs of numbers \textbf{X_i} and \textbf{Y_i} - the coordinates of the next nail. All coordinates does not exceed the modulo \textbf{10^9}. It is guaranteed that no two are not the same nail. Input data ending line containing \textbf{0}. \OutputFile For each test case in a separate line output the desired area with the two characters after the decimal point.