Putting in a number with more than 16 digits makes segmentation fault.

When I try synthesizing `123456789012345678901234567`, a segmentation fault occurs. When there are more than 16 digits next to each other (spaces don't matter), the program crashes.

```./sam "123456789012345678901234567"
zsh: segmentation fault (core dumped)  ./sam "123456789012345678901234567"
```