int right_echo_pin = 6;
int right_trigger_pin = 7;
-int left_motor_speed_pin = 8;
-int left_motor_forward_pin = 9;
-int left_motor_backward_pin = 10;
+int left_motor_forward_pin = 8;
+int left_motor_backward_pin = 9;
+int left_motor_speed_pin = 10;
int left_echo_pin = 11;
int left_trigger_pin = 12;