#include 
#include 
#include 
#include 
using namespace std;
int from_binary_to_decimal(string s) {
    int power_of_two = 1;
    int sum = 0;
    for(int i = s.size() - 1; i >= 0; i--) {
        if(s[i] == '1') {
            sum += power_of_two;
        }
        power_of_two *= 2;
    }
    return sum;
}
string from_decimal_to_binary(int x) {
    string s = "";
    while(x > 0) {
        s += (x % 2)  + '0';
        x /= 2;
    }
    reverse(s.begin(), s.end());
    return s;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    cout << from_binary_to_decimal("101") << " " << from_binary_to_decimal("1") << endl;
    cout << from_decimal_to_binary(5) << endl;
    return 0;
 
}