# Bridge over a rough river

Time Limit: 1000MS

Memory Limit: 65536K

## Description

A group of *N* travelers (1 ≤ *N* ≤ 50) has approached an old and shabby bridge and wishes to cross the river as soon as possible. However, there can be no more than two persons on the bridge at a time. Besides it's necessary to light the way with a torch for safe crossing but the group has only one torch.Each traveler needs *t*_{i} seconds to cross the river on the bridge; *i*=1, ... , *N* (*t*_{i} are integers from 1 to 100). If two travelers are crossing together their crossing time is the time of the slowest traveler.The task is to determine minimal crossing time for the whole group.

## Output

The output contains one line with the result.