vector

Ana and Barbu are playing a new game. They chose a one-dimensional array v, with n positive integer components, numbered from 0 to n-1. The first component of one-dimensional array (v[0]) is 0. The other components are non-zero positive integers.
They alternate in executing moves of the following kind on this one-dimensional array: they choose a position i (0 < i < n) and an integer value x (0 < x <= v[i]), and then v[i] drops by x, and v[i-1] increases by x.
Ana has the first move. The player that can't execute any more operations loses.

Task

Determine if Ana has a sure winning strategy or not. If Ana has a sure win strategy find out the pair (i, x) that represents the first move that can be made by him so that Ana continues to have a winning strategy.

Input Data

Line one of input file vector.in contains number n. The next line contains positive integers v[1], v[2], ..., v[N-1], each separated by a space.

Output Data

Line one of input file vector.out will contain digit 1 if Ana has a sure winning strategy or digit 0 if she doesn't. If Ana has a sure winning strategy, line two will contain the two positive integers, i and x, separated by a single space, representing the first optimum move for Ana. If there is more than one solution, the solution with i minimum will be displayed. If there is more than one solution with i minimum, the solution with x minimum will be displayed.

Restrictions

Example

vector.in

vector.out

3
1947 1986

1
1 1947

Time limit: 0.1 seconds/test

Tiberiu-Lucian Florea
University of Bucharest, Mathematics & IT Department
Contact:tiberiu.florea@gmail.com