Field Imperfection

Suppose that a field for the World Cup is being constructed. The field is intended to have dimensions of $300$ feet long by $200$ feet wide. However, due to human imperfection, the error in the length measurement is a RV $X \sim \text{Unif}(-15,15)$ and the error in the width measurement is a RV $Y \sim \text{Unif}(-5,15)$, independent of $X$. Hence, the true dimensions are $300+X$ and $200+Y$. Find the expected area of the field.