func_code_string: #include <bits/stdc++.h>   using namespace std;   long long int n;   int check(long long k) {     long long patsum = 0, nn = n, pat;     while (nn > 0) {       nn = nn - k;       pat = nn / 10;       nn = nn - pat;       patsum += pat;       if (patsum > n / 2) {         return 1;       }     }     return 0;   }   long long bs() {     long long left = 1, right = n, k;     while (left < right) {       k = (right + left) / 2;       if (check(k)) {         left = k + 1;       } else         right = k;     }     return left;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     long long t = 1, k, pat, patsum = 0, ori, flag = 0;     while (t--) {       cin >> n;       long long ans = bs();       cout << ans << endl;     }     return 0;   }   