# ['A', 'B', 'C', 'D'] -> 'A, B, C and D'.

S = ['A', 'B', 'C', 'D']

print('Løsning 1')

T = ''
for s in S[:-2]:
    #print('T =', T)
    T = T + s + ', '
#print('T =', T)
T = T + S[-2] + ' and ' + S[-1]
print(T)

print('Løsning 2')

T = ', '.join(S[:-1]) + ' and ' + S[-1]
print(T)