Here is an interesting fact about letters A, B, C, D .
Letter A,B,C,D do not appear in the spelling of 1 to 99
Letter D comes for the first time in 100 .
Letter A,B,C do not appear in the spelling of 1 to 999
Letter A comes for the first time in 1000 .
Ltr B, C do not appear in the spelling of 1 to 999,999,999
Ltr B appear for the first time in billion
Ltr C do not appear any where in the spelling of english counting .
