import numpy as np N = int(input()) A = list(map(int, input().split())) F = np.fft.fft(A) # 振幅スペクトルを計算 amplitude = np.abs(F) F_amplitude = amplitude / N * 2 F_amplitude[0] = F_amplitude[0] / 2 v = 0 hz = 0 for i in range(len(F_amplitude)): if v<F_amplitude[i]: hz=i v=F_amplitude[i] L = ['C4','D4','E4','F4','G4','A4','B4'] HZ = [260,293,326,347,391,435,489] V = [0]*7 for i in range(7): for k in range(1,7): for j in range(3): V[i]+=F_amplitude[HZ[i]*k+j] ans = 0 v = 0 for i in range(7): if v<V[i]: ans=i v=V[i] print(L[ans])