It's the ending of another well played chess game. You're the white player, and you still have a rook and your king. Your opponent only has his king left.
Since you're white, it's your turn. Create a program to play this chess match. Its output can be a sequence of moves, a gif animation, ASCII art or whatever you like.
It seems quite obvious, but I'll state it explicitly: you have to win the game (in a finite number of moves). It's always possible to win from this position. DO NOT LOSE THAT ROOK. DO NOT STALEMATE.
Your program may or may not accept a human input for the starting position and for each black move (you can safely assume this is a legal position, i.e. the kings are not touching each other). If it doesn't, a random starting position and random movements for the black king will suffice.
Your score will be length in byte of your code + bonus. Any language is allowed, lowest score wins.
-50 if your program allows both a human defined starting position and a random one. Humans can enter it via stdin, file, GUI...
-100 if your program allows both a human and a random player to move the black king
+12345 if you rely on an external chess solver or a built-in chess library
Extra rule: The match must be played until checkmate. Black does not resign, doesn't jump outside the chessboard and doesn't get kidnapped by aliens.