Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

Input: Consider Input: Question: Does progression rates and sample size estimate for PPMS based on the CLIMB study population?
Answer: Our modern PPMS cohort is demographically similar to previously studied cohorts. PPMS is associated with faster disability accrual than ROMS. Current real-world observations of time to sustained progression will inform design of new clinical trials for PPMS.

Output: yes

Input: Consider Input: Question: Is lubricin a product of megakaryocyte stimulating factor gene expression by human synovial fibroblasts?
Answer: Lubricin is secreted by synovial fibroblasts via expression of the MSF gene. Lubricin is constructed of MSF exons 6 through 9 but the presence of other exons cannot be excluded. Lubricin/MSF is the only lubricating component in the final lubricating fraction of human synovial fluid.

Output: yes

Input: Consider Input: Question: Does hIV-2 protect against HIV-1 infection in a rural community in Guinea-Bissau?
Answer: There was no protective effect of HIV-2 in this population. HIV-2 cannot be regarded as a vaccine, but, instead, may be a risk factor for HIV-1 infection.
Output: no