20 20
00000000001111111111
00000000001111111111
00000000111111111111
00000001111111111111
00000001111111111111
00000001111111111111
00000001111111111111
00111111111111111111
00111111111111111111
00111111110000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000
11111111100000000000