#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;
int main(int argc, char** argv)
{
string T;
cin >> T;
vector<int> vTemp;
int iResult;
for (int i = 0; i < T.size(); i++)
{
int iTemp = stoi(T.substr(i, 1));
vTemp.push_back(iTemp);
}
for (int i = 0; i < vTemp.size(); i++)
{
iResult += vTemp[i];
}
cout << iResult;
return 0;
}
기본 string과 substr다루기