B"Everybody knows that lucky numbers are positive integers that contain only lucky digits 4 and 7 in their decimal representation. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not. Polo the Penguin have two positive integers l and r (l xe2 x80 x89< xe2 x80 x89r), both of them are lucky numbers. Moreover, their lengths (that is, the number of digits in the decimal representation without the leading zeroes) are equal to each other. Let's assume that n is the number of distinct lucky numbers, each of them cannot be greater than r or less than l, and ai is the i-th (in increasing order) number of them. Find a1 xc2 xb7a2 xe2 x80 x89+ xe2 x80 x89a2 xc2 xb7a3 xe2 x80 x89+ xe2 x80 x89... xe2 x80 x89+ xe2 x80 x89an xe2 x80 x89- xe2 x80 x891 xc2 xb7an. As the answer can be rather large, print the remainder after dividing it by 1000000007 (109 xe2 x80 x89+ xe2 x80 x897). The first line contains a positive integer l, and the second line contains a positive integer r (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89l xe2 x80 x89< xe2 x80 x89r xe2 x80 x89 xe2 x89 xa4 xe2 x80 x8910100000). The numbers are given without any leading zeroes. It is guaranteed that the lengths of the given numbers are equal to each other and that both of them are lucky numbers. In the single line print a single integer -- the answer to the problem modulo 1000000007 (109 xe2 x80 x89+ xe2 x80 x897)."...