#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
char ch[10];
int main() {
  int ans = 0;
  scanf("%s", ch + 1);
  for (int i = 1; i <= 7; i++) {
    int tmp;
    if (ch[i] == 'A')
      tmp = 1;
    else {
      if (ch[i] == '1' && ch[i + 1] == '0')
        tmp = 10, i++;
      else
        tmp = ch[i] - '0';
    }
    ans += tmp;
  }
  cout << ans;
  return 0;
}
