#include <iostream>
#include <chrono>
#include <thread>
using namespace std;
using namespace chrono;
int fibonacci_2(int i) {
       if(i <= 0) return 0;
       if(i == 1) return 1;
       return fibonacci_2(i - 1) + fibonacci_2(i - 2);
}
void time_consumption() {
    int n;
    while (cin >> n) {
        milliseconds start_time = duration_cast<milliseconds >(
            system_clock::now().time_since_epoch()
        );

        fibonacci_2(n);

        milliseconds end_time = duration_cast<milliseconds >(
            system_clock::now().time_since_epoch()
        );
        cout << milliseconds(end_time).count() - milliseconds(start_time).count() 
            <<" ms"<< endl;
    }
}
int main()
{
    time_consumption();
    return 0;
}