Fix a prime number $p$.
Let $F$ be the geometrically connected Fermat curve of exponent $p$ over a number field $K$, i.e., $F$ is given by the equation $x^p+y^p = z^p$. Consider the same equation over the ring of integers $O_K$. Note that this scheme, denoted by $\mathcal{F}$, is normal. Note that $\mathcal{F}$ is smooth over the complement of the $p$ in $O_K$.
How does one obtain the minimal resolution of singularities of $\mathcal{F}$?
The singular fibre is a genus zero curve $(x+y-z)^p =0$ of multiplicity $p$.