P25567 [AtCoder] Sum Equals Xor
普及+
题目描述

Problem Statement

You are given a positive integer L in base two.
How many pairs of non-negative integers (a, b) satisfy the following conditions?

  • $a + b \leq L$
  • $a + b = a \text{ XOR } b$

Since there can be extremely many such pairs, print the count modulo 10^9 + 7.
What is XOR?
The XOR of integers A and $B, A \text{ XOR } B$, is defined as follows:

  • When $A \text{ XOR } B$ is written in base two, the digit in the 2^k'$s place (k \geq 0)$ is 1 if either A or B, but not both, has 1 in the 2^k's place, and 0 otherwise.

For example$, 3 \text{ XOR } 5 = 6.$ (In base two: $011 \text{ XOR } 101 = 110.)$

Input

Input is given from Standard Input in the following format:
L

Output

Print the number of pairs (a, b) that satisfy the conditions, modulo 10^9 + 7.

Constraints

  • L is given in base two, without leading zeros.
  • $1 \leq L < 2^{100$\ 001}

Sample Input 1

10

Sample Output 1

5

Five pairs (a, b) satisfy the conditions: (0, 0), (0, 1), (1, 0), (0, 2) and (2, 0).

Sample Input 2

1111111111111111111

Sample Output 2

162261460

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
10
样例输出
5