IMPA/p900/p900.cpp

#include <algorithm>
#include <array>
#include <iostream>
#include <map>
#include <utility>
#include <vector>
#include <iomanip>
#include <sstream>
#include <climits>
#include <queue>
#include <list>

using namespace std;

typedef unsigned long long nat;

int main()
{
    nat len;

    while(cin >> len)
    {
        if(!len)
            break;

        cout << "Read len: " << len << endl;

        nat result = 1;

        for(nat i = 1; i <= len/2; ++i)
        {
            nat new_combinations = pow((i+1), (len - 2*i)) - 2*(i+1);
            result += new_combinations;
            cout << "Found " << new_combinations << " for i = " << i << " Result so far: " << result << endl;
        }
        cout << result << endl;
    }
    return 0;
}