John and Brus believe that the digits 4 and 7 are lucky and all others are not. According to them, an almost lucky number is a number that contains at most one non-lucky digit in its decimal representation. Return the total number of almost lucky numbers between **a** and **b**, inclusive.

Each line contains two integers a,b<=10^16

For each line of input,output the total number of almost lucky numbers between **a** and **b**, inclusive.

```
4 7
8 19
```

```
4
4
```