Superdiagonals

The superdiagonal of a matrix $m$ is formed by the elements $m[i][j]$ in the matrix for which the column is one position more than the row: $j = i+1$ (see https://en.wikipedia.org/wiki/Main_diagonal#superdiagonal); that is, those elements lying along the diagonal just above the main diagonal. Write a program that computes the sums of the superdiagonals of several matrices.

Input

Input is a sequence of cases. Each case starts with a nonnegative integer $n$ , followed by a square $n \times n$ matrix of integers.

Output

The sum of the superdiagonal elements of each matrix, in the same order, each in a line of its own.

Problem information

Author: José Luis Balcázar

Generation: 2026-05-04T15:00:24.292Z