CF134A Average Numbers

You are given a sequence of positive integers $ a_{1},a_{2},...,a_{n} $ . Find all such indices $ i $ , that the $ i $ -th element equals the arithmetic mean of all other elements (that is all elements except for this one).

The first line contains the integer $ n $ ( $ 2

Print on the first line the number of the sought indices. Print on the second line the sought indices in the increasing order. All indices are integers from $ 1 $ to $ n $ . If the sought elements do not exist, then the first output line should contain number $ 0 $ . In this case you may either not print the second line or print an empty line.