1.e4 e5
1.e4 e5 2.Nf3
1.e4 e5 2.Nf3 Nc6
1.e4 e5 2.Nf3 Nc6 3.Bb5
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6
invalid move NC6: square does not exist: C6
1.e4 e5