#include #define rep(i,n) for (int i = 0; i < (n); ++i) #define printVec(v) printf("{"); for (const auto& i : v) { std::cout << i << ", "; } printf("}\n"); #define ALL(obj) (obj).begin(), (obj).end() #define debug(x) cout << #x << ": " << x << '\n'; #define degreeToRadian(deg) (((deg)/360)*2*M_PI) #define radianTodegree(rad) (((rad)/2/M_PI)*360) template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; using P = pair; using ll = long long; const ll INF = 1LL<<60; const int MOD = 1e9 + 7; const int dx[4] = {1, 0, -1, 0}; const int dy[4] = {0, 1, 0, -1}; //cin.tie(0);ios::sync_with_stdio(false); //cout << fixed << setprecision(15) << y << endl; int main() { int N; cin >> N; cin.ignore(); vector A; for (int i = 0; i < N; i++) { string s; getline(cin, s); if (s.find(' ') != string::npos) { cout << "assert" << endl; } else { A.push_back(s[0] - '0'); } } set st; for (int i = 0 ; i < N; i++) { for (int j = i + 1; j < N; j++) { st.insert(A[i] + A[j]); } } cout << *(++st.rbegin()) << endl; return 0; }