func_code_string: #include <bits/stdc++.h>   using namespace std;   set<int> m;   using namespace std;   bool check(int a) {     m.erase(m.begin(), m.end());     int i = 0;     while (a > 0) {       int re = a % 10;       m.insert(re);       a /= 10;       i++;     }     if (m.size() == i) {       return true;     } else       return false;   }   int main() {     int l, r, flag = 0;     long long int ans = 0;     cin >> l >> r;     for (int i = l; i <= r; i++) {       if (check(i) == true) {         ans = i;         flag = 1;         break;       }     }     if (flag == 1) {       cout << ans << endl;     } else       cout <<  -1  << endl;   }   