The company that you are auditing has the following standards:

Standard direct labor-hours	0.2	hours per unit
Standard direct labor rate	$18.00	per hour
Standard cost	$1.85	per unit

They budgeted for production of 3500 units but actual production was 3800 units. The company used 715 direct labor hours to produce the units. The actual labor rate was $16.85 per hour. What is the labor efficiency variance? (F or U)