Baxter Corporations master budget calls for the production of 6,700 units per month and $233,160 indirect labor costs for the year. Baxter considers indirect labor as a component of variable factory overhead cost. During April, the company produced 4,670 units and incurred indirect labor costs of $12,500. What amount would be reported in April as a flexible-budget variance for indirect labor? Is this variance favorable (F) or unfavorable (U)?