import sys
from Bio import SeqIO

def count_gc(seq):
    return float((seq_record.seq.count("G") + seq_record.seq.count("C"))) * 100 / len(seq_record.seq)

if __name__ == '__main__':
    fasta = sys.argv[1]
    highest_id = ""
    highest_content = 0
    for seq_record in SeqIO.parse(fasta, "fasta"):
        c = count_gc(seq_record)
        if c > highest_content:
            highest_id = seq_record.id
            highest_content = c

    print highest_id
    print "{0:.6f}".format(highest_content)