Linear Systems & Matrices · Easy problem

Let $A = \begin{bmatrix} 4 & -1 \\ 2 & 5 \end{bmatrix}$. A matrix $X$ satisfies $A + X = \begin{bmatrix} 1 & 3 \\ 0 & 2 \end{bmatrix}$. Find the entry in row $1$, column $1$ of $X$.