#P1383E. Strange Operation
Strange Operation
Description
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 $10^9+7$ ($1000000007$)?
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 $s_i = 1$.
On a single line print the answer to the problem modulo $10^9+7$ ($1000000007$).
Input
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 $s_i = 1$.
Output
On a single line print the answer to the problem modulo $10^9+7$ ($1000000007$).
Samples
000
3
0101
6
0001111
16
00101100011100
477
Note
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.