#include “iostream” #include “string” using namespace std; char a[1000005]; int main() { string s; while (cin >> s&&s != “0”) { int t = s.size(); int i,sum=0; for (i = 0; i < t; i++) { a[i] = s[i] - ‘0’; sum = sum + a[i]; } while (sum>9) { int n = 0; while (sum > 0) { n = n + sum % 10; sum = sum / 10; } sum = n; } cout << sum << endl; } }
