#include <iostream>
#include <vector>
using namespace std;
int n;string d;
vector <int> t;
void solve()
{while(n--){int pos = 0;for(int i = 0;i<t.size();i++){t[i]*=2;if(pos){t[i]+=1;pos = 0;}if(t[i]>=10) pos = 1;t[i]%=10;}if(pos) t.push_back(1);}}
int main()
{cin >> n >> d;int flag;for(int i = d.size()-1;i>=0;i--){if(d[i] != '.') t.push_back(d[i]-'0');else{flag = d.size()-i-1;}}solve();if(t[flag-1] >=5){t[flag]+=1;}for(int i = t.size()-1;i>=flag;i--){cout << t[i];}return 0;
}