Input: The program receives as input the number N <= 15, which is the number of rows and columns in the array. Next, the input stream contains N lines of N numbers that are elements of the array.
Output: The program should print a single number - the arithmetic mean of the elements of the side diagonal of a two-dimensional array.
Examples
| # |
Input |
Output |
| 1 |
3
5 26 17
20 5 29
29 23 14
|
17.000000 |