original = input('Enter the sentence: ')
original = original.upper()
command = ''
dictSim1 = []
dictSim2 = []
k = 0

while command != 'exit':
    sim1 = input('The letter: ')
    sim2 = input('is equal: ')
    sim1 = sim1.upper()
    sim2 = sim2.upper()
    dictSim1.append(sim1)
    dictSim2.append(sim2)
    newSentence = ''

    for i in range(len(original)):
        if original[i] == sim1:
            newSentence = newSentence + sim2
        elif original[i] == sim2:
            newSentence = newSentence + sim1
        else:
            newSentence = newSentence + original[i]

    print(newSentence)
    print()

    for k in range(len(dictSim1)):
        print(str(k+1) + ': ' + dictSim1[k] + ' = ' + dictSim2[k], end = ' | ')

    print()
    original = newSentence
    command = input('\nEnter the EXIT to exit :) or press ENTER to continue ')
    print()