SOLVE
LATER
Once Happy was playing with his friends during his maths class. Seeing this, his teacher asked him to solve a problem. The teacher gave him a set of n positive integers and asked him to tell the sum of the product of elements of all the possible subsets.
For e.g. Say, the teacher gave him a set {2, 3, 5}. The possible subsets of this set are {2}, {3}, {5}, {2, 3}, {2, 5}, {3, 5} and {2, 3, 5}. So Happy should report the answer as the sum of 2, 3, 5, 6 (2 * 3), \(10\) (2 * 5), \(15\) (3 * 5) and \(30\) (2 * 3 * 5) i.e., \(71\) to the teacher.
As the output of the problem can be large, so the teacher asked happy to report the answer modulo \(10^9\)+7 (\(1000000007\)).
INPUT:
The first line of input contains an integer n denoting the number of elements in the set and the next line consists of n space separated integers. The i^{th} integer is denoted by a_i.
OUTPUT:
Print the answer modulo \(10^9\)+7 (\(1000000007\)).
Constraints:
1 ≤ n ≤ \(10^5\)
0 ≤ a_i ≤ \(10^7\)
For sample input, the set consists of 3 integers 2, 3 and 5. The possible subsets of this set are {2}, {3}, {5}, {2, 3}, {2, 5}, {3, 5} and {2, 3, 5}. The product of elements of the subsets are 2, 3, 5, 6, 10, 15 and 30. The sum of these products is 71. So the answer is 71%(10^9+7) = 71.