Language: C++

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
//#pragma warning(disable : 4996)


#ifdef _MSC_VER
#include <intrin.h>

#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include<atcoder/all>


using namespace std;
using namespace atcoder;


#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
using ll = long long;
#define print(x) cout << (x) << endl
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
//#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i, v.size()) cout << v[i] << " \n"[i==(int)v.size()-1]
template <typename T1, typename T2> inline void chmin(T1& a, T2 b) { if (a > b) a = b; }
template <typename T1, typename T2> inline void chmax(T1& a, T2 b) { if (a < b) a = b; }
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 1e9+7;
constexpr int MAX = 300010;
const double pi = acos(-1);
constexpr double EPS = 1e-8;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;
void Yes(bool cond) { cout << (cond ? "Yes" : "No") << '\n'; }
void YES(bool cond) { cout << (cond ? "YES" : "NO") << '\n'; }


vector<pair<long long, int>>factorize(long long x) {
	vector<pair<long long, int>>ret;
	for (long long i = 2; i*i <= x; i++) {
		if (x % i == 0) {
			pair<long long, int> res = { i,0 };
			while (x%i == 0) {
				res.second++;
				x /= i;
			}
			ret.push_back(res);
		}
	}
	if (x != 1) {
		ret.push_back({ x,1 });
	}
	return ret;
}

long long extGCD(long long a, long long b, long long &x, long long &y) {
	if (b == 0) {
		x = 1;
		y = 0;
		return a;
	}
	long long d = extGCD(b, a%b, y, x);
	y -= a / b * x;
	return d;
}
void solve() {
	int N; cin >> N;
	int M = 2 * N;
	vector<pii>factors = factorize(M);
	int sz = factors.size();
	vector<int>f(sz);
	REP(i, sz) {
		int x = 1;
		REP(_, factors[i].second)x *= factors[i].first;
		f[i] = x;
	}
	ll ans = LINF;
	REP(bit, 1LL << sz) {
		int a = 1, b = 1;
		REP(i, sz) {
			if (bit&(1LL << i)) {
				a *= f[i];
			}
			else b *= f[i];
		}
		a *= -1;
		int x,  y;
		extGCD(a, b, x, y);
		if (x >= 1 && y >= 1) {
			ll k = -a * x;

			chmin(ans, k);
		}
	}
	print(ans);
}




signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	//int q;
	//cin >> q;
	//while (q--)
	solve();

}


Compiler output:
a.cc:40:9: fatal error: atcoder/all: No such file or directory
   40 | #include<atcoder/all>
      |         ^~~~~~~~~~~~~
compilation terminated.