func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   const int N = 1e5 + 2;   const int M = 1 << 19;   const int inf = 2e9;   const long long linf = 1e18;   long long n, m, k;   int ok(long long mid) {     long long ans = 0;     for (int i = 1; i <= n; i++) {       ans += min(m, mid / i);     }     return ans >= k;   }   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     cin >> n >> m >> k;     long long l = 1, r = n * m, ans = 0;     while (l <= r) {       long long mid = l + r >> 1;       if (ok(mid)) {         r = mid - 1;         ans = mid;       } else         l = mid + 1;     }     cout << ans <<   n ;     return 0;   }   