Sequences

Let $x_1 < x_2 < \dots < x_n$ be positive integers, and let $x_1$ and $x_2$ be relatively prime, so the only positive integer that divides both of them is $1$.

Consider every infinite, strictly increasing sequence of integers whose first member is $0$ and in which the difference between any two adjacent members equals one of $x_1, x_2, \dots, x_n$. For example, with $n = 2$, $x_1 = 4$ and $x_2 = 7$, the first nine members of such a sequence can be $0, 4, 8, 15, 19, 26, 33, 40, 44$.

Write a program that finds the largest integer appearing in none of these sequences.

The first line contains the integer $n$ ($1 < n < 6$).

The second line contains the integers $x_1, x_2, \dots, x_n$ separated by spaces, with $2 \le x_1 < x_2 < \dots < x_n \le 10\,000$. The values $x_1$ and $x_2$ are relatively prime.

Print the integer you found on the first line.