Given an m x n matrix mat where every row is sorted in strictly increasing order, return the smallest common element in all rows.

If there is no common element, return -1.

 

Example 1:

Input: mat = [[1,2,3,4,5],[2,4,5,8,10],[3,5,7,9,11],[1,3,5,7,9]]
Output: 5

Example 2:

Input: mat = [[1,2,3],[2,3,4],[2,3,5]]
Output: 2

 

Constraints:

• m == mat.length
• n == mat[i].length
• 1 <= m, n <= 500
• 1 <= mat[i][j] <= 104
• mat[i] is sorted in strictly increasing order.