You have a field of N boosters. The power of i^th booster is given as A_i. If you stand on i^th booster, you will get the power A_i and you can make a jump of length A_i. That is, if you are standing on 3^rd booster and it's power is 5, then you will land on position 8. Currently, you are standing outside the field to the left of first booster and you want to across this field by reaching to the right of N^th booster. You want to make only one jump to any booster such that you will finally land to right of N^th booster. Print the minimum length of initial jump you should make such that you will finally land outside the field by using exactly one booster.

INPUT:
First line of input consists of integer N. Next line consists of N integers A₁, A₂...A_N.

OUTPUT:
Output the minimum length of jump you should make such that you will finally land outside the field using exactly 1 booster.

CONSTRAINTS:
1 ≤ N ≤ 10⁴
1 ≤ A_i ≤ 10⁴