(1) two years - for a minor offense; (2) five years - for a medium grave offense; (3) seven years - for a grave offense; (4) ten years - for a special grave offense. 3. The following periods of sentence enforcement shall be established in respect of persons described in paragraph 1 of this Article: (1) two years - where a person was sentenced to any punishment other than imprisonment, or to imprisonment for a minor offense; (2) five years - where a person was sentenced to imprisonment for a medium grave offense, or imprisonment for a term up to five years for a grave offense; (3) seven years - where a person was sentenced to imprisonment for a term exceeding five years for a grave offense; (4) ten years - where a person was sentenced to imprisonment for a special grave offense. Article 107. Parole 1. Parole may be applied to persons who serve their sentence of imprisonment imposed for an offense crime committed at the age under 18, regardless of the gravity of the offense. 2. Parole may be applied, if a person displays decent behavior and diligence in work and studies as a proof of his/her reformation. 3. Parole may be applied to persons, who committed an offense at the age under 18, after they have actually served: (1) not less than one-third of the term of imprisonment imposed by a court for a minor or medium grave offense, and also for a reckless grave offense; (2) not less than one-half of the term of imprisonment imposed by a court for an intended grave offense or reckless special grave offense, and also where that person had previously served a sentence of imprisonment imposed for an intended offense but committed another intended offense at the age under 18 before the conviction was canceled or revoked and had been sentenced for that offense to imprisonment; (3) not less than two-thirds of the term of imprisonment imposed by a court for an intended special grave offense, and also where that person had previously served a sentence of imprisonment and had been paroled but committed another intended offense at the age under 18 before the end of sentence and had been sentenced for that offense to imprisonment; 4. Commutation of the unserved part of the sentence shall not be applied in respect of minors. 5. Where a paroled person commits another offense during the remaining part of the sentence, a court shall impose a punishment under the rules provided for by Articles 71 and 72 of this Code.