#include <bits/stdc++.h>   using namespace std;   long long int mod = 1000000007;   int main() {     ios_base ::sync_with_stdio(false);     cin.tie(NULL);     long long int n;     cin >> n;     if (n == 1) {       cout << 2;       return 0;     }     if (n == 2) {       cout << 3;       return 0;     }     long long int curr = 2, line = 3, to = 2;     while (to < n) {       line++;       to += curr;       if (to >= n) {         cout << line;         return 0;       }       line++;       to += (curr);       curr++;       if (to >= n) {         cout << line;         return 0;       }     }   }   