A sequence is a container that stores an ordered list of values, like nucleotides, amino acids or char values. Examples for sequences are "hello world" or "ACGT". The number of these values is called the length of the sequence. The values in a sequence are ordered. We define i − 1 to be the position of the i-th value in a sequence, i.e., the first value in the sequence stands at position 0 and the last at position length−1, as it is standard in C. We call 0 the begin position and the length of the sequence the end position. Note that the end position is not the position of the last value in the sequence but the position after the last value.