#include //#include using namespace std; //using namespace atcoder; //using mint = modint1000000007; //const int mod = 1000000007; //using mint = modint998244353; //const int mod = 998244353; //const int INF = 1e9; //const long long LINF = 1e18; #define rep(i, n) for (int i = 0; i < (n); ++i) #define rep2(i,l,r)for(int i=(l);i<(r);++i) #define rrep(i, n) for (int i = (n-1); i >= 0; --i) #define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i) #define all(x) (x).begin(),(x).end() #define allR(x) (x).rbegin(),(x).rend() #define endl "\n" #define P pair template inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; } const vector freqs{ 261.6, 294.3, 327.0, 348.8, 392.4, 436.0, 490.5 }; const vector str{ "C4","D4","E4","F4","G4","A4","B4" }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; vectora(n); rep(i, n)cin >> a[i]; int idx = -1; long long val = -1; rep(i, freqs.size()) { long long subval = 0; int diff = n / freqs[i]; rep(j, n) { int nj = (j + diff) % n; subval += a[n] * a[nj]; } if (chmax(val, subval)) idx = i; } cout << str[idx] << endl; return 0; }