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 main diagonal of a two-dimensional array.
Examples
| # |
Input |
Output |
| 1 |
5
23 23 2 5 24
7 21 15 12 18
14 16 6 19 15
23 5 23 9 24
5 7 12 18 28
|
17.400000 |