Happy numbers again

Limits: 4 sec., 256 MiB

This statement was translated automatically from Ukrainian.

Everyone knows that a happy number is one whose decimal representation contains only fours and sevens. For example, the numbers 4, 7, 47, 7777, and 4744474 are happy.

Zenyk considers a pair of happy numbers \(x < y\) to be interesting if \(x\) \(AND\) \(y = 0\), where \(AND\) is the bitwise "AND" operation.

Can you count how many interesting pairs of numbers there are in the range \([L, R]\)?

Input

The single line contains two integers separated by a space — \(L\) and \(R\).

Output

Print a single integer — the number of interesting pairs \(x\) and \(y\) such that \(L \le x < y \le R\).

Constraints

\(1 \le L \le R \le 10^{18}\).

Samples

Input (stdin) сopy	Output (stdout) сopy
4 77	1

Input (stdin) сopy	Output (stdout) сopy
1 1000	6

Notes

In the first test, the only pair of numbers that satisfy the problem condition is \(4\) and \(74\).