Interesting mate in 15

[bnst]

CHEST version 3.19b, 12-Apr-2008
Options = -r -M 8192 -S -U -lll -z15
Input file: STDIN
Reading job:
# Search for mate in 15
W: Kh2 Qg1 Pb3 (3)
B: Ka5 Bh1 Pb6 Pb4 Pc6 Pg7 Pg2 (7)
FEN: 8/6p1/1pp5/k7/1p6/1P6/6pK/6Qb w - -
analysing (mate in 15 moves):
Solution (in 15 moves):
Qg1 - a1
Time (real) = 6792 sec (ca. 113.2 min) (ca. 1.9 hrs)

Qa1+ Kb5 Kg1 g6 Qh8 g5 Qa1 ...+7
c5 Qe8+ ...+2
Kc5 Qe5#
-*- Qa8+ ...+11
g5 Qh8 g4 Qa1 ...+4
c5 Qe8+ ...+2
Kc5 Qe5#
-*- Qa8+ ...+8
Kc5 Qe5#
c5 Qa4#

end of solution tree (no duals except at top)
Total Time (real) = 6792 sec (ca. 113.2 min) (ca. 1.9 hrs)

It didn't take too long with Chest.
Regards
anst