Chess coins (2)

Consider a square chess board with $n$ rows and $n$ columns, where every square contains a number of coins. Write a program such that, given a chess board, computes the total number of coins on the diagonals. The first square in the board (top left) is always white.

Input

The input is a natural number $n>0$ , followed by $n$ rows, each with $n$ non-negative integers, separated by whitespaces.

Output

The ouput is the total number of coins in the board diagonals.

Problem information

Author: Lluís Padró

Generation: 2026-01-25T17:05:11.658Z