CF319A.Malek Dance Club
普及/提高-
通过率:0%
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题目描述
As a tradition, every year before IOI all the members of Natalia Fan Club are invited to Malek Dance Club to have a fun night together. Malek Dance Club has 2n members and coincidentally Natalia Fan Club also has 2n members. Each member of MDC is assigned a unique id i from 0 to 2n−1 . The same holds for each member of NFC.
One of the parts of this tradition is one by one dance, where each member of MDC dances with a member of NFC. A dance pair is a pair of numbers (a,b) such that member a from MDC dances with member b from NFC.
The complexity of a pairs' assignment is the number of pairs of dancing pairs (a,b) and (c,d) such that a<c and b>d .
You are given a binary number of length n named x . We know that member i from MDC dances with member from NFC. Your task is to calculate the complexity of this assignment modulo 1000000007 (109+7) .
Expression denotes applying «XOR» to numbers x and y . This operation exists in all modern programming languages, for example, in C++ and Java it denotes as «^», in Pascal — «xor».
输入格式
The first line of input contains a binary number x of lenght n , (1<=n<=100) .
This number may contain leading zeros.
输出格式
Print the complexity of the given dance assignent modulo 1000000007 (109+7) .
输入输出样例
输入#1
11
输出#1
6
输入#2
01
输出#2
2
输入#3
1
输出#3
1