write a go solution for 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<=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)?

Input Format:
The only line of input contains binary string s (1<=|s|<=10^6). For all i (1<=i<=|s|) s_i=0 or s_i=1.

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

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: 0101arrow0(10)1arrow011arrow0(11)arrow01.
- to obtain 11 from 0101 Koa can operate as follows: 0101arrow(01)01arrow101arrow1(01)arrow11.

Parentheses denote the two positions Koa selected in each operation.. Output only the code with no comments, explanation, or additional text.