Submission

Score: 100

User: rice_ot

Problemset: มุมขวาบน

Language: cpp

Time: 0.003 second

Submitted On: 2025-10-14 15:04:33

#include <bits/stdc++.h>
using namespace std;

int main(){
    int n; cin>>n;
    int start = 1;
    vector<int> corner;
    corner.push_back(1);
    for(int i = 6; start<n; i+=8){
        start+=i;
        corner.push_back(start);
    }

    //for(auto& i : corner) cout<<i<<" ";

    if(corner.back() - n == 2) cout<<"Cannot find top-right corner.";
    else{
        cout<<corner[corner.size()-2];
    }
}