E. Strange Operationtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputKoa 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)?InputThe 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.OutputOn a single line print the answer to the problem modulo 10^9+7 (1000000007).ExamplesInput
000
Output
3
Input
0101
Output
6
Input
0001111
Output
16
Input
00101100011100
Output
477
NoteIn 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.
000

3 
['combinatorics', 'data structures', 'dp', '*2800']