#include<string>
#include<cmath>
using namespace std;
int main() {
    cout<<"input a number:";
    int i;
    int sum=0;
    double pwr=0;
    cin>>i;
    if(i<10) {
      if(i%9==0)
        cout<<"is";
      else
        cout<<"is not";
    }
    else
    {
      while(i/(static_cast<int>(pow(10,pwr)))>=10)
        pwr++;
      cout<<pwr<<endl;  
        
      while(pwr>=0) {
          int j;
          j=i/(static_cast<int>(pow(10,pwr)));
          i=i%(static_cast<int>(pow(10,pwr)));
          pwr--;
          sum+=j;
          cout<<"j="<<j<<endl;
    }
    cout<<"sum="<<sum<<endl;
    if((sum%9)==0)
        cout<<"这个数能被9整除";
    else  
        cout<<" is not";
    }
    system("pause");
    return 0;
}