data = [
    [13, 25, 23, 34],
    [45, 32, 44, 47],
    [12, 33, 23, 95],
    [13, 53, 34, 35]
]
sum_ = 0
index = -1
for row in data:
    # print(row)
    sum_ += row[index]
    index -= 1
print(sum_) 