1661 Cow Parenthesis


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Points: 100
Time limit: 1.0s
Memory limit: 32M

Problem types
Allowed languages
C, C++, Java, Python

Description

Recently, the cows have been competing with strings of balanced parentheses and comparing them with each other to see who has the best one.

Such strings are scored as follows (all strings are balanced): the string "()" has score 1; if "A" has score s(A) then "(A)" has score 2s(A); and if "A" and "B" have scores s(A) and s(B), respectively, then "AB" has score s(A)+s(B). For example, s("(())()") = s("(())")+s("()") = 2s("()")+1 = 2*1+1 = 3.

Bessie wants to beat all of her fellow cows, so she needs to calculate the score of some strings. Given a string of balanced parentheses of length N (2 <= N <= 100,000), help Bessie compute its score.

Input

(多组数据)

  • Line 1: A single integer: N

  • Lines 2..N + 1: Line i+1 will contain 1 integer: 0 if the ith

      character of the string is '(',  and 1 if the ith character of
      the string is ')'

Output

  • Line 1: The score of the string. Since this number can get quite
      large, output the  score modulo 12345678910.

Sample

Input

6
0
0
1
1
0
1

Output

3

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