Penalty calculation

The penalty rule of the second kriiICPC is too complicated, so the organizers decided to hand the penalty computation to you.

Suppose you sent $n$ submissions for one problem. The $i$-th submission ($1 \le i \le n$) was sent $t_i$ minutes after the contest started and scored $s_i$ points.

The penalty $P$ for this problem is defined as follows. Let $f$ be the smallest $k$ with $s_k = \max\{s_1, s_2, \dots, s_n\}$, that is, the index of the earliest submission among those with the highest score. Then $P$ is:

• if $s_f = 0$, then $P = 0$
• if $s_f = 1$ or $s_f = 4$, then $P = t_f + (f - 1) \times 20$

Given the submissions you sent for one problem, write a program that computes the penalty you get on it.

The first line contains the number of submissions $n$ ($1 \le n \le 100$).

Each of the next $n$ lines contains two integers $t_i$ and $s_i$ separated by a space. It is guaranteed that $1 \le t_1 < t_2 < \cdots < t_n \le 300$, and each $s_i$ is 0, 1, or 4.

Print the value of $P$ on the first line.