Time Limit: 2 Seconds
Memory Limit: 65536 KB
The chess endgame "a king and a queen versus a king" is known to
be easy victory for the side that has a queen.
The position in such an endgame is described by the locations of three figures:
the white king, the white queen, and the black king. Locations are written in
a usual chess notation, constructed from a letter from "a" to "h",
which determine vertical line, and the digit from 1 to 8, which determine horizontal
line of the location.
Given the position described, you are find a move for the white queen by which
the black king will be checkmated, or determine that no such a move exists.
The input file contains three two-character locations for the white king, white
queen, and black king, in that order, separated by spaces.
The input position is a valid chess position for the white's turn, i.e. all
figures occupy different spaces, kings are not located in the neighboring squares,
and the black king is not under the check.
Process to the end of file.
Output file must contain the two-character location - destination square for
the white queen's move. If checkmating move does not exist, output file must
contain the string "no". If there is more than one checkmating move,
you may output any one of them.
a3 g2 a1
Source: Northeastern Europe 2001, Far-Eastern Subregion