Consider the data type `Punct`, defined as follows: ``` struct Punct { int x, y; }; ``` where `x` and `y` are the integer coordinates of a point in the plane. Read from standard input a natural number `n` (`n >= 2`), followed by the coordinates of `n` points. Print the two points at the smallest Euclidean distance, then the square of that distance. Distinct points may share a coordinate; if multiple pairs achieve the same minimum distance, print the first one in lexicographic order by indices (smallest `i` first, then smallest `j`). The point with the smaller index is printed first.