Heading error from a constant gyro bias

A stationary robot uses a single-axis gyroscope to track its heading by integrating angular rate. The gyro has an uncompensated constant bias of $0.5\,^\circ/\text{s}$ and is otherwise noise-free. The robot does not actually rotate during the test. If you integrate the gyro output for $60$ seconds, what heading error (in degrees) will have accumulated? Assume the bias is constant and you start from zero error.