In this task, you are given a sentence. You are expected to write the name of the organism substances in the body mentioned in the input. Although there might be several correct answers, you need to write one of them.

Example Input:  Intra - operative monitoring of partial pressure of tissue oxygen ( PtiO2 ) is a very sensitive method of detecting the decrease of oxygen for cell utilization , due to decreased blood flow , during temporary clipping and after definitive clipping , in middle cerebral artery incidental unruptured aneurysm surgery .
Example Output: blood

Example Input:  Sputum 0 1 1 0
Example Output: Sputum

Example Input:  ( B ) Real - time PCR was performed on total RNA samples from the human brain regions known to express MOR1 .
Example Output:
samples