rhyme = str(input('Enter the 1st. line of nursery rhyme : '))
start = int(input('Enter start number for display : '))
end = int(input('Enter end number for display : '))
# 截断字符串包含start位不包含end位
print('this is the 1st. line \n {0} \n and this is truncated {1}'.format(rhyme, rhyme[start:end]))