Compiling:
$ mkdir -p build
$ javac -cp src -d build com/witt/chess/Main.java

Running:
twittmac:chess-study twitt$ java -cp build com.witt.chess.Main
Please enter the board dimensions:
M:7
N:7
Please enter the piece set (example: KKKQQBBNR):kkqqbbn
Print all solutions (Y/N)?n
Sample solution:
. . Q . . . .
B . . . . . B
. . . Q . . .
. K . . . . N
. . . . . . .
. . . . . . .
. . . . K . .

Number of solutions: 3063828
Processing time: 65432 ms.