Staircase Search

We are given a row and column wise sorted array in which we have to search for a particular key. If found, return the index values else return -1.
For eg:
INPUT:
Array :
1      4      8    10
2      5      9    15
6     16    18   20
11   17    19   23
Key to search: 17

OUTPUT:
Key found at row=3 and column=1
