#include using namespace std; const int MOD = (1e9+7); void printmat(const vector>& mat) { for (auto row : mat) { for (auto elem : row) cout << elem << " "; cout << endl; } } void printv(const vector& v) { for (auto elem : v) cout << elem << " "; cout << endl; } void printvs(const vector>& vs) { for (auto row : vs) { for (auto elem : row) cout << elem << ", "; cout << endl; } } void printht(const unordered_map& ht) { for (auto elem : ht) cout << elem.first << " : " << elem.second << endl; } void printmp(const map& ht) { for (auto elem : ht) cout << elem.first << " : " << elem.second << endl; } void printst(const set& st) { for (auto elem : st) cout << elem << " "; cout << endl; } vector primeFactors(int n) { vector ans; while (n % 2 == 0) { ans.push_back(2); n = n/2; } for (int i = 3; i*i <= (n); i = i + 2) { while (n % i == 0) { ans.push_back(i); n = n/i; } } if (n > 2) ans.push_back(n); return ans; } int find_f(const vector& uf, int i) { while (uf[i]!=i) i = uf[i]; return i; } bool union_f(vector& uf, vector& sz, int a, int b) { a = find_f(uf, a); b = find_f(uf, b); //cout << "a, b = " << a << ", " << b << endl; if (a==b) return false; if (sz[a] < sz[b]) { //cout << "sz[a], sz[b] = " << sz[a] << ", " << sz[b] << endl; //cout << "a, b = " << a << ", " << b << endl; swap(a,b); //cout << "a, b = " << a << ", " << b << endl; } sz[a] += sz[b]; uf[b] = a; return true; } long long helper(long long num) { num *= 2; long long x = sqrt(num); if (x*(x+1)==num) return x; else return -1; } int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); int T=1, caseIdx=0; //cin >> T; while (T--) { //caseIdx++; int n, k=100; cin >> n; while (k--) { //cout << n << endl; string s = to_string(n); int sum = 0; for (auto c : s) sum += (c-'0'); n = sum; } cout << n << endl; //cout << "Case #" << caseIdx << ": " << s << endl; } }