CF1383E.Strange Operation

普及/提高-

通过率：0%

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题目描述

Koa the Koala has a binary string $s$ of length $n$ . Koa can perform no more than $n-1$ (possibly zero) operations of the following form:

In one operation Koa selects positions $i$ and $i+1$ for some $i$ with $1 \le i < |s|$ and sets $s_i$ to $max(s_i, s_{i+1})$ . Then Koa deletes position $i+1$ from $s$ (after the removal, the remaining parts are concatenated).

Note that after every operation the length of $s$ decreases by $1$ .

How many different binary strings can Koa obtain by doing no more than $n-1$ (possibly zero) operations modulo $10^9+7$ ( $1000000007$ )?

输入格式

The only line of input contains binary string $s$ ( $1 \le |s| \le 10^6$ ). For all $i$ ( $1 \le i \le |s|$ ) $s_i = 0$ or $s_i = 1$ .

输出格式

On a single line print the answer to the problem modulo $10^9+7$ ( $1000000007$ ).

输入输出样例

输入#1
```
000
```
输出#1
```
3
```
输入#2
```
0101
```
输出#2
```
6
```
输入#3
```
0001111
```
输出#3
```
16
```
输入#4
```
00101100011100
```
输出#4
```
477
```

说明/提示

In the first sample Koa can obtain binary strings: $0$ , $00$ and $000$ .

In the second sample Koa can obtain binary strings: $1$ , $01$ , $11$ , $011$ , $101$ and $0101$ . For example:

to obtain $01$ from $0101$ Koa can operate as follows: $0101 \rightarrow 0(10)1 \rightarrow 011 \rightarrow 0(11) \rightarrow 01$ .
to obtain $11$ from $0101$ Koa can operate as follows: $0101 \rightarrow (01)01 \rightarrow 101 \rightarrow 1(01) \rightarrow 11$ .

Parentheses denote the two positions Koa selected in each operation.

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