a+b+c=19 a +b+c=19.
a+b=14 => a=14-b. =>
b+c=16 c=16-b
14-b+b+16-b=19. 30-b=19
a=14-b. =>a=14-b. =>
c=16-b. b=16-b
-b=19-30. b=11. b=11
a=14-b. =>a=14-11. =>a=3
c=16-b. c=16-11. c=5