/** * code generated by JHelper * More info: https://github.com/AlexeyDmitriev/JHelper * @author aajisaka */ #include using namespace std; void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << " " << to_string(H); debug_out(T...); } #ifdef LOCAL #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__) #else #define debug(...) 42 #endif #define SPEED ios_base::sync_with_stdio(false);cin.tie(nullptr) #define rep(i,n) for(int i=0; i<(int)(n); i++) #define all(v) v.begin(), v.end() template inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } using ll = long long; using ull = unsigned long long; using P = pair; constexpr long double PI = 3.14159265358979323846264338327950288L; mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()); class No1168DigitSumSequence { public: void solve(istream& cin, ostream& cout) { SPEED; int n; cin >> n; for(int i=0; i<99; i++) { int p = 0; while(n > 0) { p += n%10; n /= 10; } n = p; } cout << n << endl; } }; signed main() { No1168DigitSumSequence solver; std::istream& in(std::cin); std::ostream& out(std::cout); solver.solve(in, out); return 0; }