give binary string s return number substring character 1 since answer large return modulo 109 7 Example 1input s 0110111output 9explanation there 9 substre total 1s characters1 5 times11 3 times111 1 timeexample 2input s 101output 2explanation Substring 1 show 2 time sExample 3input s 111111output 21explanation each substring contain 1s character Constraints1 slength 105si 0 1