Math with Lego Blocks

Replace every 0 in the two arrays with an arbitrary positive integer, keeping the other values unchanged, so that the two totals are equal and as small as possible; output −1 if there is no solution. The filled values are not limited by the original arrays' upper bound of 10000.

输入格式

The first line contains n m, the second line contains rowA, and the third line contains rowB; 1≤n,m≤100000, original elements 0..10000.

输出格式

Output a single integer, the answer.

样例 1

输入：

2 1
0 2
3

输出：

3

样例 2

输入：

1 2
1
0 0

输出：

-1

样例 3

输入：

2 1
0 0
0

输出：

2

样例说明

The outputs of the three public examples are, in order: 3; -1; 2. These answers were verified by independent enumeration or direct simulation.