Pizza Delivery

Flatland is a 1D country — all points in Flatland lie on one line. Everybody in Flatland loves pizza (because it's flat enough). There are $n$ pizzerias numbered $1$ through $n$, which serve $m$ consumers numbered $1$ through $m$. Let's denote the position of the $i$-th pizzeria by $s_i$ and the position of the $i$-th consumer's home by $c_i$. No two pizzerias are located at the same position,