from random import randint

def rule(l):
    return l[1]+l[0]

a = [(3,57), (40,11), (55,7)]

a.sort(reverse=True, key=rule)

print(a)

def pechat():
    for i in range(len(matrix)):
        for j in range(len(matrix[i])):
            print(f"{matrix[i][j]:4}", end=' ')
        print()

n = 5
matrix = [[randint(-50, 50) for j in range(n)] for i in range(n)]
pechat()
matrix.sort(reverse=True)
print('='*30)
pechat()

#i==j
X = [matrix[i][i] for i in range(len(matrix))]

#j == n-1-i
Y = [matrix[i][n-1-i] for i in range(len(matrix))]

print(X)
print(Y)