1) CH3 - CH2 - CH(CH3) - CH(CH2-CH3) - CH2 - CH2 - CH2 - CH3
2) CH3 - CH2 - C(CH3)(CH3) - CH(CH2-CH3) - CH2 - CH2 - CH2 - CH3
1) CH3 - CH2 - CH(CH3) - CH(CH2-CH3) - CH2 - CH2 - CH2 - CH3
2) CH3 - CH2 - C(CH3)(CH3) - CH(CH2-CH3) - CH2 - CH2 - CH2 - CH3