p403.ans1
======================
3

=================
p403.ans2
======================
5

=================
p403.cpp
======================
#include <bits/stdc++.h>

using namespace std;

template<typename T1, typename T2>
ostream& operator<<(ostream& out, const pair<T1, T2>& x) {
    return out << x.first << ' ' << x.second;
}

template<typename T1, typename T2>
istream& operator>>(istream& in, pair<T1, T2>& x) {
    return in >> x.first >> x.second;
}

template<typename T>
istream& operator>>(istream& in, vector<T>& a) {
    for(auto& x: a) {
        in >> x;
    }
    return in;
};

template<typename T>
ostream& operator<<(ostream& out, const vector<T>& a) {
    for(auto x: a) {
        out << x << ' ';
    }
    return out;
};

int64_t x;

void read() { cin >> x; }

void solve() {
    // We need an integer n whose positive predecessors 1..n-1 sum to x times
    // n, i.e. (n - 1) * n / 2 = x * n. Cancelling n gives n = 2 * x + 1.

    cout << x * 2 + 1 << '\n';
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    read();
    solve();

    return 0;
}

=================
p403.in1
======================
1

=================
p403.in2
======================
2

=================
statement.txt
======================
403. Scientific Problem
Time limit per test: 0.25 second(s)
Memory limit: 65536 kilobytes
input: standard
output: standard



Once upon a time Professor Idioticideasinventor was travelling by train. Watching cheerless landscape outside the window, he decided to invent the theme of his new scientific work. All of a sudden a brilliant idea struck him: to develop an effective algorithm finding an integer number, which is x times less than the sum of all its integer positive predecessors, where number x is given. As far as he has no computer in the train, you have to solve this difficult problem.

Input
The first line of the input file contains an integer number x (1 ≤ x ≤ 109).

Output
Output an integer number — the answer to the problem.

Example(s)
sample input
sample output
1
3

sample input
sample output
2
5

=================
