- Time limit: 1.00 s
- Memory limit: 512 MB
The first input line has an integer $n$: the size of the grid. The rows and columns are numbered $1,2,\dots,n$.
The next line has $n$ integers $a_1,a_2,\ldots,a_n$: You must choose exactly $a_i$ squares from the $i$th row.
The las line has $n$ integers $b_1,b_2,\ldots,b_n$: You must choose exactly $b_j$ squares from the $j$th column.
Print $n$ lines describing which squares you choose (
Xmeans that you choose a square,
.means that you don't choose it). You can print any valid solution.
If it is not possible to satisfy the conditions print only $-1$.
- $1 \le n \le 50$
- $0 \le a_i \le n$
- $0 \le b_j \le n$
0 1 3 2 0
1 2 2 0 1