def remove_nucleotide(genome, mutation):
if mutation.lower() not in genome.lower():
return 0
nucleotide_group = genome.lower().split(mutation.lower())
longest_group = max(nucleotide_group[:-1], key=len)
if longest_group == '':
return 1
if longest_group == nucleotide_group[-2]:
return len(longest_group) + 1
return len(longest_group)
print(remove_nucleotide("IUVZLIZ", "Z"))
print(remove_nucleotide("ATCGATCG", "G"))
print(remove_nucleotide("MOMOZ", "M"))
print(remove_nucleotide("AAAA", "A"))