99camry replace O2 sensor

Hi,
Is anyone who knows where is the bank1 sensor1?
The check engine light on my 99camry V6 is on. The code is P0135.
It is found to be the O2 sensor, bank1,sensor1.
So is there anybody who know the exact position of sensor1 and sensor2.
Thanks.

bank 1 is the o2 sensor closes to the fire wall. bank 1 sensor 2 should be the next following sensor down the exhaust.