import math
import cmath


def main():
    N = int(input())
    *A, = map(int, input().split())

    melody = [
        ("C4", 261.6),
        ("D4", 294.3),
        ("E4", 327.0),
        ("F4", 348.8),
        ("G4", 392.4),
        ("A4", 436.0),
        ("B4", 490.5),
    ]

    ans = 0
    ansv = 0

    for m, f in melody:
        angle = 2*math.pi*f/N
        s = 0
        for i in range(N):
            s += A[i] * cmath.exp(angle*1j)
        if ans < abs(s):
            ans = abs(s)
            ansv = m

    print(ansv)


if __name__ == '__main__':
    main()