conversion

#include <iostream>
#include <cmath>

int to_decimal(int n, int num);
int from_decimal(int n, int num);

int main()
{
    std::ios_base::sync_with_stdio(0);
    int P;
    std::cin >> P;
    std::cout << from_decimal(to_decimal(P, 2), 2) << "\n";
}

int to_decimal(int n, int num)
{
    int res = 0;
    for (int i = 0; n; i++)
    {
        res += (n % 10) * pow(num, i);
        n /= 10;
    }
    return res;
}

int from_decimal(int n, int num)
{
    int res = 0;
    for (int i = 0; n; i++)
    {
        res += (n % num) * pow (10, i);
        n /= num;
    }
    return res;
}