Score : $200$ points
You have a digit sequence $S$ of length $4$. You are wondering which of the following formats $S$ is in:
01 for January), concatenated in this orderIf $S$ is valid in only YYMM format, print YYMM; if $S$ is valid in only MMYY format, print MMYY; if $S$ is valid in both formats, print AMBIGUOUS; if $S$ is valid in neither format, print NA.
Input is given from Standard Input in the following format:
$S$
Print the specified string: YYMM, MMYY, AMBIGUOUS or NA.
1905
YYMM
May $XX19$ is a valid date, but $19$ is not valid as a month. Thus, this string is only valid in YYMM format.
0112
AMBIGUOUS
Both December $XX01$ and January $XX12$ are valid dates. Thus, this string is valid in both formats.
1700
NA
Neither $0$ nor $17$ is valid as a month. Thus, this string is valid in neither format.