The magical world of has now upgraded and stores in information in 2D prefix sum arrays. This helps them move faster and saves a lot of time. Yet, as usual, they sometimes lose the initial arrays and get stuck. Can you help them restore the initial 2D array from a given 2D prefix sum matrix?
The first line of the input contains two integers - the number of rows in the matrix r and the number of columns c (1 ≤ r, c ≤ 1000).
The next r lines contain c integers separated by a space, that represent the elements in the prefix sum matrix .
The program should print r lines containing c numbers representing the initial matrix.