The sum of the last diagonal X29958


Statement
 

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Write a program to find the sum of the last diagonal of the matrix. Given matrix MM with RR rows and CC columns. Its last diagonal always contains element MR,CM_{R,C}

Input

The first line provides two numbers: RR and CC the number of rows and columns in the matrix respectively. 0≤R,C≤10000 \le R,C \le 1000. Next RR lines with CC integer numbers follows. All the absolute values of the matrix are less than or equal to 10910^9.

Output

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

Public test cases

  • Input

    2 2
1 3
3 1

    Output

    2

  • Input

    1 2
1 2

    Output

    2

  • Input

    3 2
2 4
4 6
1 1

    Output

    5
    • Information
    Author
    Dmitry Bufistov
    Language
    English
    Translator
    Original language
    Spanish
    Other languages
    Spanish
    Official solutions
    C++ Python
    User solutions