Input to this problem will consist of a (non-empty) series of up to 100 data sets. Each data set will be formatted according to the following description, and there will be no blank lines separating data sets.
A single data set has 3 components:
- Start line - A single line, "START N", where 1 <= N <= 20.
- Viral code - A sequence of N alphanumeric characters. Alphanumeric characters will consist of an uppercase letter (A-Z) or a digit (0-9).
- End line - A single line, "END"
Following the final data set will be a single line, "ENDOFINPUT".