In the analysis of DNA sequences the initial main target is often shorter sequences that occur repeatedly within a longer sequence. Suppose we want to investigate the DNA sequence ATAGGCCTTATGCCATTAC. We want to know if a given subsequence of a maximum of 4 bases occurs at least once or twice or not at all in the longer sequence.
A line containing a short DNA sequence of at least one and up to four bases long.
A line containing "not", "once" or "at least twice", depending on the the frequency of the short sequence from the input within the longer DNA sequence ATAGGCCTTATGCCATTAC.
Input:
TT
Output:
at least twice