The sum of the last diagonal

Write a program to find the sum of the last diagonal of the matrix. Given matrix $M$ with $R$ rows and $C$ columns. Its last diagonal always contains element $M_{R,C}$

Input

The first line provides two numbers: $R$ and $C$ the number of rows and columns in the matrix respectively. $0 \le R,C \le 1000$ . Next $R$ lines with $C$ integer numbers follows. All the absolute values of the matrix are less than or equal to $10^9$ .

Output

Print one integer number - the sum of the last diagonal.

Problem information

Author: Unknown

Generation: 2026-01-25T15:00:05.517Z