Sample size for a fixed-width interval

Let $X_{1},X_{2},…,X_{n}$ be a random sample of size $n$ $(n>1)$ from a $N(\mu,1)$ distribution, where $\mu\in\mathbb{R}$ is an unknown parameter. If $\bar{X}=\dfrac{1}{n}\sum_{i=1}^{n}X_{i}$, then the minimum value of $n$ such that $P(2\bar{X}-1<2\mu<2\bar{X}+1)\ge 0.99$ equals __________ (in integer) [You may use $\Phi(2.58)=0.9951$, $\Phi(2.48)=0.9934$]