IR-MO 2002 Problem 11

In an $m\times n$ table there is a policeman in cell $(1,1)$ , and there is a thief in cell $(i,j)$ . A move is going from a cell to a neighbor (each cell has at most four neighbors). Thief makes the first move, then the policeman moves and ... For which $(i,j)$ the policeman can catch the thief?