Project Euler Forum

Could anyone please clarify me problem #24 of project euler? I'm not a native english speaker, so I found it tought to understand.

Thanks in advance

There are 6 permutations of the digits 0,1,2.
012
021
120
102
210
201.

If I sort those numbers in the order of their digits, I get
012
021
102
120
201
210
We call this sorted list the lexicographic order of those six permutatations.
As 120 is the fourth one of this list the fourth lexicographic permutation of the digits 0,1,2 is 120

I'm currently struggling with this one, can anybody give a hint or two? Thank you.

The first number is 0123456789. Next one is 0123456798. Try to guess, when first digit will change from 0 to 1.