

cpp
#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;
}