Integers in decimal notation (i.e. decimal integers) are formed using base 10, with the decimal digits 0 to 9 representing the values zero to nine.
Here are some examples of valid decimal integers
100 0 7453 000005
decimal-integer = digit-sequence
digit-sequence = digit { digit }
digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'