IntermediatePrefix Sums2000 ms256 MB

Workshop Capacity

Given attendance counts for sessions and a range `l` to `r`, print the total attendance in that inclusive range.

Statement

Given attendance counts for sessions and a range `l` to `r`, print the total attendance in that inclusive range.

Input

First line: `n`. Second line: `n` integers. Third line: `l r`.

Output

Print the range sum.

Constraints

  • Positions are 1-indexed.

Examples

Example 1

Input

5
9 12 10 8 11
2 4

Output

30

Sessions 2 through 4 total 12 + 10 + 8.

Sample runs use visible examples. Full submissions are checked securely on the server, and private test cases are not shown in the browser.