Linear Functions

There are $N$ linear functions of the form $f(x) = ax + b$. The $i$-th function is $f_i(x) = a_i x + b_i$.

For each function, substitute a different integer from $1$ to $N$ as its $x$, using each of the $N$ integers exactly once. Find the maximum possible sum of the values $f(x)$ over all functions.

Specifically, choose a permutation $x_1, x_2, \ldots, x_N$ of length $N$ that maximizes $\sum_{i=1}^N a_i x_i + b_i$.

The first line contains the number of linear functions $N$. $(1 \le N \le 100{,}000)$

From the second line onward, the next $N$ lines each contain two integers $a_i$ and $b_i$, separated by a space, that describe the $i$-th function. $(0 \le a_i, b_i \le 10^9)$

Print the answer to the problem on the first line.