Kata

So yet again aliens are in near earth orbit. Instead of using their standard annihilation protocol, they are flashing their big spaceship headlights towards earth. You, with your phD in saving the earth, have identified this as morse code! It's up to you to decode these messages and save planet earth once again, or not.

INPUT will be a string in morse code:

e.g.

'. . .   _   . _   . _ .   _       _ . _ .   _ _ _   . . _   _ .   _   . .   _ .   _ _ .       _   _ _ _   . . . _ _'

the encoding is only from alphabets and numbers.

OUPUT should be a string made of alphabets and numbers:

e.g. 'start counting to 3'

Inter[national|galactic] Morse Code:

1. The length of a dot is one unit.
2. A dash is three units.
3. The space between parts of the same letter is one unit.
4. The space between letters is three units.
5. The space between words is seven units.

  a  = . _  
  b  = _ . . .  
  c  = _ . _ .  
  d  = _ . .  
  e  = .  
  f  = . . _ .  
  g  = _ _ .  
  h  = . . . .  
  i  = . .  
  j  = . _ _ _  
  k  = _ . _  
  l  = . _ . .  
  m  = _ _  
  n  = _ .  
  o  = _ _ _  
  p  = . _ _ .  
  q  = _ _ . _  
  r  = . _ .  
  s  = . . .  
  t  = _  
  u  = . . _  
  v  = . . . _  
  w  = . _ _  
  x  = _ . . _  
  y  = _ . _ _  
  z  = _ _ . .  
  1 = . _ _ _ _  
  2 = . . _ _ _  
  3 = . . . _ _  
  4 = . . . . _  
  5 = . . . . .  
  6 = _ . . . .  
  7 = _ _ . . .  
  8 = _ _ _ . .  
  9 = _ _ _ _ .  
  0 = _ _ _ _ _