#include<iostream>
#include <queue>
#include<string>
#include<vector>
#include<map>
#include<algorithm>
#include<math.h>
#include <iomanip>
#include <algorithm>
#pragma warning(disable:4996)
using namespace std;
int stringtoint(string a)
{
int count = 1;
int res=0;
int sum = a.size();
for (;sum > 0;sum--)
{
res += (a[sum - 1]-'0') * count;
count *= 10;
}
return res;
}//string转int
int main()
{
string a;
int n;
cin >> a>>n;
int s = a.size();
//cout << s << endl;
string b="";
for (int i=0;i<n;i++)
{
b = b + a[i+s-n];
}
for (int i = 0;i < s - n;i++)
{
b = b + a[i];
}
double a_i = double(stringtoint(a));
double b_i = double(stringtoint(b));
//cout << a_i << " " << b_i << endl;
printf("%.2f", b_i / a_i);
}