Submission

Score: 100

User: helloskibidi

Problemset: มุมขวาบน

Language: cpp

Time: 0.004 second

Submitted On: 2026-10-06 09:37:02

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

int main(){
    int n ;
    long long k=0; 
    cin >> n;
    if(n==1) { cout << 1 ; return 0;}
    while(4*k*k + 2*k + 1 <= n && n != 4*k*k + 2*k-1) k++;
    
    
    if(n == 4*k*k + 2*k-1) cout << "Cannot find top-right corner.";
    else if(n==4*k*k + 2*k) cout << 4*k*k + 2*k;
    else if(n<4*k*k + 2*k + 1){k-- ; cout << 4*k*k + 2*k + 1;}
}