Arrange the digits 1, 1, 2, 2, 3, 3 as a six-digit number

Arrange the digits 1, 1, 2, 2, 3, 3 as a six-digit number in which the 1s are separated by one digit, the 2s are separated by two digits and 3s are separated by three digits. There are two answers. Find one.

As 3s should be separated by 3 digits, there are only two possibilities for the number;

3 * * * 3 * or * 3 * * * 3

As 2s are separated by 2 digits;

3 * 2 * 3 2 or 2 3 * 2 * 3

Filling out 1s the numbers are 3 1 2 1 3 2 or 2 3 1 2 1 3 

The numbers are 312132 and 231213.