Stack Weights

You have n coins, each of which has a distinct weight. There are two stacks which are initially empty. On each step you move one coin to a stack. You never remove a coin from a stack. After each move, your task is to determine which stack is heavier (if we can be sure that either stack is heavier). Input The first input line has an integer n: the number of coins. The coins are numbered 1,2,\do