For two nonnegative integers $a, b$, let $a \wedge b$ be their bitwise AND, and $a \vee b$ be their bitwise OR.
You are given an array $A_0, A_1, \ldots, A_{2^N - 1}$ of length $2^N$ consisting of nonnegative integers. Please find a pair of indices $0 \le i, j \le 2^N - 1$ such that $A_{i} + A_{j} < A_{i \wedge j} + A_{i \vee j}$, or state that no such pair exists. If there is more than one such pair, find any one of them.
Input
The first line contains an integer $N$ ($0 \leq N \leq 20$).
The second line contains $2^N$ integers: $A_0, A_1, \ldots, A_{2^N - 1}$ ($0 \leq A_i \leq 10^7$).
Output
If there is an answer, output two integers $i$ and $j$ denoting the answer. The numbers $i$ and $j$ should be in the range $[0, 2^N - 1]$. Otherwise, output -1.
Examples
Input 1
2 0 1 1 2
Output 1
-1
Input 2
2 0 1 1 3
Output 2
2 1
Input 3
0 100
Output 3
-1