sentence1: What is the unit digit in -LSB- math -RSB- -LRB- 13 ! -RRB- ^ -LCB- 31 ! -RCB- -LSB- / math -RSB- ?
sentence2: What is the unit digit of -LSB- math -RSB- 137 ^ -LCB- 13 ^ -LCB- 47 -RCB- -RCB- -LSB- / math -RSB- ?