11381번 - Sequences 서브태스크다국어

Let x₁ < x₂ < … < x_n be positive integers and let x₁ and x₂ be relatively prime (i.e. the only positive integer that evenly divides both of them is 1).

We consider all infinite sequences of integers, which are strictly increasing with first member 0, for which the difference between any two adjacent members is equal to one of the integers x₁, x₂, …, x_n. For example, if n = 2, x₁ = 4 and x₂ = 7, then the first nine members of such a sequence are possible to be 0, 4, 8, 15, 19, 26, 33, 40, 44.

Write program sequence that determines the largest integer that cannot be found in any of these sequences. 

The integer n (1 < n < 6) is given on the first line of the standard input. There are n integers on the second line: x₁, x₂, …, x_n. 

On a line of the standard output the program have to write the sought integer.