#736. Matrix: Sum of the other diagonal
You are given a matrix of integers. **Sum of the other diagonal**.
### Input
The first line has n n, each of the next n lines has n integers (a square matrix).
### Output
The answer.
Examples
Input
4 4 7 6 7 6 -7 -9 -3 -4 0 5 0 -8 -2 -5 9 -9
Output
6
Input
3 3 -4 -1 -2 3 0 7 5 -2 -5
Output
3
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.