def expand_cigar(cigar):
    """
    From short CIGAR version to long CIGAR version
    where each character is each nts in the sequence.

    Args:
        *cigar(str)*: CIGAR string.

        >>> 10MA3M

    Returns:
        *cigar_long(str)*: CIGAR long.

        >>> MMMMMMMMMMAMMM
    """
    cigar_long = ""
    n = 0
    for nt in cigar:
        if nt in ["D", "M", "I", "A", "T", "C", "G"]:
            if n > 0:
                cigar_long += nt * int(n)
            else:
                cigar_long += nt
            n = 0
        else:
            if n > 0:
                n = int("%s%s" % (n, nt))
            else:
                n = int(nt)
    return cigar_long