`@Huyyy`

#include <bits/stdc++.h>
using namespace std;

bool ktnt(int n) {
  if (n <= 1) {
    return false;
  }
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      return false;
    }
  }
  return true;
}

int main() {
  long long n,s=0;
  cin >> n;
  while (n > 0) {
    int d = n % 10;
    if (ktnt(d)) {
      s += d;
    }
    n /= 10;
  }
  if (s == 0) {
    cout << -1 << endl;
  } else {
    cout << s << endl;
  }
  return 0;
}

$#doanthevu$

Code C++:

#include <bits/stdc++.h>
#define ll long long
using namespace std;
bool gg(ll n) {
    if (n < 2) return false;
    for (ll i = 2; i * i <= n; i++) {
        if (n % i == 0) return false;
    }
    return true;
}
ll qq(ll n) {
    ll sum = 0;
    while (n > 0) {
        ll dg = n % 10;
        if (gg(dg)) {
            sum += dg;
        }
        n /= 10;
    }
    return sum;
}

int main() {
    ll n;
    cin >> n;
    cout << qq(n) << endl;
    return 0;
}