1TONES = ('C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B')
  2INTERVALS = ('unison', 'minor 2nd', 'major 2nd', 'minor 3rd', 'major 3rd', 'perfect 4th', 'diminished 5th', 'perfect 5th', 'minor 6th', 'major 6th', 'minor 7th', 'major 7th')
  3SEMITONES = 12
  4
  5class Tone:
  6    def __init__(self, tone):
  7        self.tone = tone
  8
  9    def __str__(self):
 10        return str(self.tone)
 11
 12    def __add__(self, other):
 13        if isinstance(other, Tone):
 14            return Chord(self, other)
 15        elif isinstance(other, Interval):
 16            semitones = other.semitones % SEMITONES
 17            self_index = TONES.index(str(self))
 18            self_index += semitones
 19            return Tone(TONES[self_index % SEMITONES])
 20        return NotImplemented
 21
 22    def __sub__(self, other):
 23        self_index = TONES.index(str(self))
 24        if isinstance(other, Tone):
 25            other_index = TONES.index(str(other))
 26            return Interval(abs(self_index - other_index))
 27        elif isinstance(other, Interval):
 28            semitones = other.semitones % SEMITONES
 29            self_index -= semitones
 30            return Tone(TONES[self_index % SEMITONES])
 31        return NotImplemented
 32
 33    def __eq__(self, other):
 34        if isinstance(other, Tone):
 35            return self.tone == other.tone
 36        return False
 37
 38    #ne znam kakvo tochno oznachava no mi izleze greshka che Tone trqbva da e hashable
 39    def __hash__(self):
 40        return hash(self.tone)
 41
 42
 43class Interval:
 44    def __init__(self, semitones):
 45        self.semitones = semitones
 46
 47    def __str__(self):
 48        return INTERVALS[self.semitones % SEMITONES] 
 49
 50    def __add__(self, other):
 51        if isinstance(other, Tone):
 52            raise TypeError('Invalid operation')
 53        elif isinstance(other, Interval):
 54            return Interval((self.semitones + other.semitones) % SEMITONES)
 55    
 56    def __sub__(self, other):
 57        if isinstance(other, Tone):
 58            raise TypeError('Invalid operation')
 59    
 60    def __neg__(self):
 61        return Interval(-self.semitones)
 62
 63  
 64class Chord:
 65    def __init__(self, *args):
 66        tones = list(set(args))
 67        if len(tones) == 1:
 68            raise TypeError('Cannot have a chord made of only 1 unique tone')
 69        else:
 70            self.root = args[0]            
 71            self.tones = tones
 72
 73    def __str__(self):
 74        output = str(self.root.tone)
 75        root_index = TONES.index(str(self.root.tone))
 76        tone_names = {str(tone) for tone in self.tones}
 77        for tone in TONES[root_index + 1:]:
 78            if tone in tone_names:
 79                output += '-' + tone
 80        for tone in TONES[:root_index]:
 81            if tone in tone_names:
 82                output += '-' + tone
 83        return output
 84        
 85    def __add__(self, other):
 86        if isinstance(other, Tone):
 87            return Chord(self.root, *self.tones, other)
 88        elif isinstance(other, Chord):
 89            return Chord(*self.tones, *other.tones)
 90        return NotImplemented
 91
 92    def __sub__(self, other):
 93        if isinstance(other, Tone):
 94            if other in self.tones:
 95                other_index = self.tones.index(other)
 96                return Chord(*self.tones[:other_index], *self.tones[other_index + 1:])
 97            else:
 98               raise TypeError(f'Cannot remove tone {other} from chord {self}') 
 99        return NotImplemented
100
101    def is_minor(self):
102        for tone in self.tones:
103            interval = self.root - tone 
104            if str(interval) == 'minor 3rd':
105                return True
106        return False
107
108    def is_major(self):
109        for tone in self.tones:
110            interval = self.root - tone
111            if str(interval) == 'major 3rd':
112                return True
113        return False
114
115    def is_power_chord(self):
116        return not (self.is_minor() or self.is_major())
117    
118    def transposed(self, interval):
119        new_tones = []
120        new_tones.append(self.root + interval)
121        for tone in self.tones:
122            new_tones.append(tone + interval)
123        return Chord(*new_tones)