func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, ans, l;   bool flag = 0;   inline long long getLen(long long x) {     long long cnt = 0;     while (x) {       cnt++;       x /= 10;     }     return cnt;   }   inline long long getSum(long long x) {     long long cnt = 0;     while (x) {       cnt += x % 10;       x /= 10;     }     return cnt;   }   int main() {     cin >> n;     long long sqn = sqrt(n);     for (l = sqn; l > 0; l--) {       if (l * l + 9 * l * getLen(l) < n) break;     }     for (ans = l; ans <= sqn; ans++) {       if (ans * ans + ans * getSum(ans) == n) {         flag = 1;         break;       }     }     printf( %lld n , flag ? ans : -1);     return 0;   }   