Create a vector that allows the user to enter as many numbers as they wish (assume they will enter at least 1 number). The user will enter non-negative numbers (greater than or equal to zero) one at a time. When the user wishes to no longer enter numbers, the user should enter -1 to signal they are done.

When the user is done entering numbers, print in order:

1. How many numbers the user entered.
2. The numbers the user entered in order.
3. The smallest number they entered.
4. The largest number they entered.
5. The first number they entered.
6. The last number they entered.